A common misconception most of us is that the system unit is protected from all sides, and therefore you should not worry about its security. In fact, if we compare the device of a computer, then the screen is the eyes, and the "systemist" is the brain. That is why it is necessary to behave as correctly as possible with such a part of the structure, only in this way the equipment will last a long time.

Why it is impossible to put the system unit on the floor without a stand:

1. Large amount of dust... The greatest amount of dust accumulation is on the floor. It settles on the nearest details, tables and lays down as an imperceptible haze on the wallpaper. But in any case, dust mostly settles on the floor. The system unit contains fans that are responsible for stabilizing the temperature of blocks, motherboards and video cards. If you put it directly on the floor, then all the dust in an even greater amount will settle on the fan blades, which in the future will contribute to the fact that the fan stops and some structural element burns out.
2. Smooth surface... To ensure the stability of the system unit, you need to place it on a perfectly flat surface. Unfortunately, 80% of all floor coverings have certain irregularities, and therefore it is impossible to guarantee stability without supply.
3. Temperature drops... The system unit must not be exposed to constant temperature changes. If you put it on a windowsill or near a battery, then you cannot expect the equipment to last a long time. Floors are capable of accumulating heat, moisture and cold at different times of the year.
4. Mechanical damage... Any scratch on the surface of the block is a potential threat of corrosion, and therefore you should be more careful about where you place the processor. Do not place it near the aisle, in a place where there is a risk of damage or overturning. You should pay particular attention to children's rooms. It is best to place the computer near a wall, but not close to it, so that condensation does not form.

These are the main reasons why programmers do not recommend placing the computer unit directly on the floor without a stand. But there are other common mistakes a PC user makes - shocks, mechanical damage, exposure to moisture, accumulation of dampness on systems. All this contributes to the fact that after a short time of use, the computer fails, it has to be repaired or replaced.

The microchips of the system unit are very susceptible to static, and therefore the location of equipment near sources of static will result in breakdown. Also, you cannot install the device on the cat's favorite resting place, and you must not allow her to sleep near the computer.

Where to put?

The first thing that comes to mind when placing a system unit is to buy a table with special stands. And if the table already exists and there is no desire to change it? What to do in this case? In this situation, there are special stands for the system unit, which are universal in their application, easy to operate and not expensive.

The main advantage of the stand is its maneuverability. The wooden base can be placed anywhere under the table, it will not interfere with work, and if necessary, you can easily change its location.

Stand for the computer system unit

A universal and only practical option for arranging a workplace with a table that does not have a stand or place to place a processor is Barsky's wooden stand. Outwardly, it is a simple H-shaped design. But, despite its simplicity, it will make life at your desk incredibly easier for you. Advantages of using a stand for the system unit:

• installed exactly relative to the surface;
• fixation of the system unit is provided due to the side borders;
• you can change the location of the processor: to the left or right side, forward or move back to the wall;
• dust accumulates under the wooden base of the bottom, and not on the processor itself;
• is transferred and does not require fastening to the base of the table, which does not contribute to the deformation of the main structure;
• lightweight natural wood without chemical impregnation will fit into any room interior.

The main task of such a stand is to ensure the stability of the block and protect it from the accumulation of moisture from the floor surface.

How to determine dimensions

System blocks differ not only in memory size, but also in external parameters: some are smaller, others are larger. How, then, to determine the required size of the stand? A special addition to the computer desk - Barsky's stand is universal. Its dimensions allow accommodating both large devices and non-standard system units: width-depth-height - 540x270x120 mm.

Next to the side part, it is possible to put a carrier or install a tee for connecting from the mains. This helps to properly organize the workplace at home or in the office.

Barsky offers

Barsky's black and white stand for a computer system unit is a combination of style, simplicity and harmony. It can be installed in any convenient place, which is important for left-handed people (often you need to adapt to the design of furniture designed for right-handers). A sturdy wooden stand with ideal shapes will help you organize your workplace as conveniently and correctly as possible, and black and white colors are suitable for any color scheme of the table.

A reward is given for finding a block of bitcoin

In May 2017, the Bitcoin network faced a major challenge. The number of unconfirmed transactions reached 200 thousand, and the total amount of raw data exceeded 120 MB. Considering that 1 block in the bitcoin network is equal to 1 MB, and the average time of its creation is about 10 minutes, the queue of 120 blocks stretched for several days, since new and new unconfirmed transactions were constantly arriving.

By increasing transfer fees, it was possible to temporarily reduce the number of unprocessed transactions in the queue, but this measure, of course, could not be considered sustainable. And it is all the more surprising that miners from time to time find and close empty blocks, that is, instead of filling them completely up to 1 MB, or 4-5 thousand transactions, the block does not contain any information related to transactions.

At some point, the number of empty blocks reached a quarter of all blocks generated by the system, and they continued to be created even when the mempool was overloaded with tens of thousands of unconfirmed transactions.

According to statistics provided by Bitfury, at the end of 2015, more than two hundred empty blocks were generated monthly, by the end of 2016, their number had dropped to several dozen. The improvements are related to an improvement in the architecture, which made it possible to increase the speed of transaction processing, however, empty blocks still continue to be created.

Bitcoin empty block statistics

What is the matter here? Let's try to figure it out.

How is a Bitcoin block created?

Each new block is a chain element that contains a set of records of network operations performed that are new from the point of view of the previous chain. A new block is added to the end of the blockchain, it also contains information about the previous state of the chain, and no further changes to its structure are possible.

That is, a continuous chain of blocks is a kind of accounting book, where all the operations that have ever been performed in the system are recorded. Any user must be sure that the accounting system is not tampered with. How is this confidence built?

The block structure includes a header - a personal solution for the block, and miners are looking for it. They take information from the block and begin to process it, performing some mathematical operations, in order to end up with a short sequence of letters and numbers that correspond to predetermined properties. This sequence is called a hash.

Miners mine bitcoins

In order for a block to be able to be written to the blockchain, it is required to find a special hash parameter, the indicator of which is lower than a predetermined value. Until the miner found this parameter by random search, the block is in operation.

If the miner finally solved the problem, then he informs the entire network about the receipt of a new block. The found block is checked by full network nodes, and after checking it is included in the blockchain. To "adjust" the processing speed to the growth of the power of the entire computing network, the complexity is recalculated every 2016 blocks so that the time to search for a new block is approximately equal to 10 minutes.

This is how the creation of a new block looks like. The hash of the last block found in the process of recalculation becomes a kind of "seal", that is, it seals the block and confirms the reliability of the entire previous chain. If someone tries to conduct a fictitious transaction by changing one of the blocks, then its hash will change, and anyone who recalculates the hash of this block will immediately detect the fake.

Now let's briefly describe the structure of the block.

Bitcoin block structure

The block consists of a header and a list of operations.

The header, as we already know, contains a hash (created using the SHA-256 algorithm), it also includes the hash property of the previous block, which creates continuous continuity between network blocks, a list of hashes of operations, block size, etc.

A special place is occupied by the Bits parameter - a shortened version of the hash value. The block will be added to the chain only when miners pick a hash less than bits.

So, the title is unique and protects the block from forgery. The block is filled with a list of transactions, each of which shows the source and recipient of the transfer.

The recipient is identified using a public (public) key, and a new transaction is created that uses money confirmed in one of the previous transactions. To confirm ownership, a digital signature is used, which certifies absolutely every operation on the network.

Of course, the structure of the network looks complicated, especially for a beginner, but as you dive into the essence of its work, the creative genius of its creator begins to manifest itself, for the first time in history, who solved the problem of a lack of security. Bitcoin cannot be copied or used twice, and the probability of an attack on the network tends to zero, since the attacker must have at his disposal the power of most of the network nodes, which becomes extremely difficult given the decentralized nature of the network.

So, we come to the most important thing. How is the miner's work structured and what does he get paid for?

Block size and miner reward

If the system as a whole pays for performing certain actions, then the pools will perform these actions in order to receive payment. This mechanism looks like this.

The miner (mining pool) receives payment for the work performed from two sources:

• Firstly, this is the reward for finding a new block, which is currently 12.5 BTC (in 2020, the reward will be halved).
• Secondly, as soon as a miner finds a new block, he is automatically paid for all transactions that are included in this block.

At the dawn of bitcoin development, blocks were far from being filled completely, often containing less than 10 transactions, but as the network grew in popularity, the block occupancy also began to grow, which led to an increase in the queue of unprocessed transactions. To increase the speed of transactions, they began to apply an increased commission, which led to another problem - the inability to use bitcoin for small payments.

Many options have been proposed to solve this problem, from increasing blocks to creating higher-level protocols used on top of the bitcoin protocol. Until recently, developers tended to use a modified Segregated Witness (SegWit) protocol called Segwit2x. With the help of it, part of the information had to be taken out of the block, that is, stored separately from the blockchain chain, and the size of the block itself had to increase to 2 MB, which theoretically made it possible to significantly speed up the passage of transactions and increase anonymity.

However, the hard fork planned for November 16 did not take place, because after the publication of its code, the community did not manage to come to a consensus.

Where do empty blocks come from?

The miner, as logic suggests, should strive to include the maximum number of transactions in the new block, since in this case his income grows. It is all the more surprising to see empty blocks created by mining. Where do they come from?

Suppose that the miner found the hash of the next block, let's call it N. Then he immediately, so as not to idle power, must start looking for block N + 1. At the same time, the miner must transfer block N to other network participants, who must download it and check the transactions included in the block. Accordingly, the miner at this moment solves two tasks simultaneously - checking transactions of block N and searching for block N + 1.

If a miner finds block N + 1 before block N is verified, does he have the right to fill it with transactions? No, it doesn't. Indeed, in these new transactions there may be those that rely on transactions included in block N, which has not yet been confirmed. Even if a queue of a large number of unconfirmed transactions has accumulated in the mempool, which must be included in block N + 1, the miner cannot do this until the confirmation of block N. And if so, then the miner closes block N + 1 empty, it will contain only one coinbase transaction, which is generated automatically and carries information about the reward for creating a block. Receives a reward and starts searching for block N + 2.

This is where empty blocks come from - this is how the blockchain works. Empty blocks are obtained due to the mismatch of the rates of confirmation of blocks and the search for the next ones, therefore, work on improving the network architecture does not stop for a moment.

Solution

So, the main problem that leads to the creation of empty blocks is the speed of information exchange. Each new block must be "presented" by the pool to other full network nodes, which, in turn, must download it to themselves, and the download speed is different for everyone, and then check all transactions in this block. All these operations take time.

At the time of this writing, the number of unconfirmed transactions exceeded 160 thousand, and the amount of raw data was 117 MB.

In 2018, it is planned to introduce several technological solutions at once that can unload the bitcoin network and increase the speed of transactions.

I was prompted to write this article by constant questions to the materials of the "" column, which quite often begin with the word " why». Why is a power supply recommended in such and such an assemblyN watt? Why do you offer such expensive solutions, because you can significantly save money? Why is a one kilowatt power supply recommended for an extreme build? This is just a small list of questions that I remembered immediately when I started writing this article. Indeed, users who do not yet have the proper experience in assembling and completing system units want to know the exact and obvious criteria for choosing a “breadwinner” for all PCs. In addition, the choice of power supplies on our market is very, very wide. So, on the website of the "Regard" store at the time of this writing, there were 676 models of computer power supplies - fewer central processors are sold. Therefore, it is necessary to help beginners understand this issue.

It is important to note that I will not recommend any specific power supply models in this article. For these purposes, on our website periodically. This material will consider the features of modern PSU models, as well as the criteria and formats of modern PC platforms that allow you to assemble a full-fledged gaming system.

⇡ How did the power consumption of gaming components change?

Before starting to analyze the main and secondary parameters of any computer power supply, in my opinion, it is necessary to figure out which PC components affect the level of power consumption. More precisely, it is clear that the Stakhanovites in this matter are the central processor and a discrete video card, but how much does this hardware affect the power consumption?

Let's keep it simple. The graphs below show the parameters of all processors and video cards that the 3DNews laboratory has tested over the past five years and which, according to the author of this material, can at least conditionally be classified as game solutions (taking into account the relevance in a certain period of time, of course). In this case, we are talking about such a parameter as TDP - the calculated thermal power. The fact is that many people associate this value with energy consumption.

Intel believes that Thermal Design Power (TDP) is a parameter that “ Indicates the average performance in watts when the processor power dissipates (when running at base clock, when all cores are engaged) under complex load conditions defined byIntel". We see that the TDP level of modern - and not very modern - central processing units varies over a fairly wide range. The statistics I have collected speak of chips with a design power of 35 and up to 250 watts, respectively. If we consider the most popular devices in their years, we will see that mainly gaming computers are installed chips with a TDP in the range from 65 to 105 watts.

And here we immediately see a certain catch. Undoubtedly, the central processing unit and video card are the main consumers of energy in any computer system. At first glance, it may seem that choosing a power supply unit of the required power is very simple: we add the TDP of the processor to the TDP of the graphics accelerator, plus we take into account that any system unit contains other components (drives, motherboard and hardware with fans). Only now, using Intel's definition, we see that the calculated thermal power is the average performance in watts when the CPU is running at the base frequency. Quite often, you can find work scenarios when the CPU for a desktop PC goes beyond the level specified by the manufacturer. In general, TDP is not a measure of the actual power consumption of a particular component.

Let me give you a simple example. Above is a screenshot that clearly demonstrates how the central processor works under load in the form of the Prime95 program. According to the technical specifications, this 6-core chip has a base frequency of 2.8 GHz and a rated power of 65 W. However, in a program that uses AVX instructions, all cores work at 3.8 GHz - this is how Turbo Boost works. Our measurements showed that the processor consumes more than 95W, which is clearly outside the limits specified by Intel in the specification. It turns out that in many motherboards the MultiCore Enhancements function, which is responsible for the operation of the CPU within the TDP, is enabled by default - therefore, the restrictions on the maximum power consumption have been removed.

We also recently learned that at the same TDP level - 65 W - it works in a similar way. , the chip frequency ranges from 4.1 to 4.4 GHz with a base value of 3.6 GHz. Naturally, 65 W is out of the question: under a serious load, the processor sets a completely different bar for power consumption - 100+ W. Again, we are talking about the system's operation in default mode, without manual overclocking or raising the voltage, that is, the manufacturer deliberately makes it so that the real power consumption significantly exceeds the declared TDP level. As you can see, both chipmakers have been acting the same lately.

A similar situation is observed among video cards. Here is the most productive gaming model to date, the GeForce RTX 2080 Ti with a declared TDP of 260 W at maximum load.

This is the catch. You can't just take and add up the calculated power of the main components of the system.... So, the sum of TDP Core i9-9900K and GeForce RTX 2080 Ti is 345 watts. Other components of the system will "eat up" a little more. However, looking ahead, I will say that I managed to load the system so that it consumed more than 450 watts.

And don't forget about overclocking. You can judge about its benefits in terms of, for example, getting additional FPS in games from our reviews - 3DNews does not miss interesting and popular models of central processors and video cards. But how the power consumption of the system changes after overclocking, you will find out in the second part of the article.

Under the phrase "other system components", naturally, we mean such hardware as a motherboard, RAM, other discrete devices (in addition to a video card), as well as components of cooling systems (cooler and case fans, an LSS pump, and so on). Only practice shows that all the listed components do not consume very much - against the background of the same processors and video cards.

* The graph above shows the level of power consumption of the entire system (description - below), not just RAM

Let's take a look at RAM. Unfortunately, I do not know of such a method that will quite accurately measure the power consumption of separate RAM modules. So I took two Samsung M378A1G43EB-CRC modules totaling 16GB and installed them in a system with a Ryzen 5 1600 processor and motherboard. We know that this kit quietly overclocks to 3200 MHz with the same latency, but a slight increase in voltage. For the load, I used the Prime95 29.8 program with the Large FFT test enabled, which loads the RAM to the maximum. Well, the difference between DDR4-2400 and DDR4-3200 is only 14W when comparing power consumption peaks.

It makes little sense to measure the energy consumption of storage devices, because against the background of the same processors and video cards, it is extremely small. For example, a review of 14-16 TB hard drives was published on our website - that these monsters do not consume more than 9.5 watts in read mode, while such drives have 7-9 platters. It turns out that only a bunch of several HDD / SSD can seriously affect the power consumption of a PC, and even then it must be borne in mind that storage devices must work simultaneously, and this is not very typical for desktops. Usually, when it comes to a home PC, the system uses 1-2 SSDs and the same number of mechanical drives.

The situation with power consumption is approximately the same for fans - parameters such as current strength, voltage and power are often indicated on their cases. Standard impellers suitable for desktop use rarely draw more than 5 watts. Typically, the system uses 3-4 case fans and one or two "Carlsons" that come with the processor cooling. It turns out that even the installation of six impellers will increase the power consumption of the system unit by only 20-25 watts.

As a matter of fact, we come to where we started. The main power consumption in any system unit falls on the central processor and video card. We have already found out that you cannot trust the passport characteristics of the CPU and GPU, and choosing a block by the sum of TDP components is not a good idea. How to understand which block is needed - we will tell you in the second part.

All of the above allows us to draw one more conclusion: we see that the power consumption of computer equipment does not change much from year to year and is within certain limits. That is, the power supply purchased now will last a long time and faithfully and will come in handy when assembling the next system, or maybe two. In this vein, buying a known good PSU looks like a very rational idea.

⇡ About cable management of the system unit

Continuing the topic of choosing a power supply unit of a certain power, it is imperative to talk about cable management in modern PCs. The fact is that one important rule works here: the more the power supply unit has, the more cables it has. If we talk about gaming systems, then in modern realities, at least two wires may be required from the power source, which will be connected to the motherboard. On average, four to five cables are used. But power supplies often have a lot more of them.

Let's start with video cards, because in most gaming PCs, they are the ones that require the most electricity. As you know, the PCI Express x16 slot of the motherboard is capable of transmitting up to 75 W of electricity to a discrete device (in fact, a little more, but the standard describes just such a value). For example, such a power supply is sufficient for most video cards of the GeForce GTX 1650 level, which can be safely classified as gaming. But on more powerful video cards, you can often find 6- and 8-pin power connectors. In the first case, up to 75 W of energy is transmitted, in the second - up to 150 W.

Mid-range video cards (with a TDP of no more than 200 W), as a rule, are equipped with one 6- or 8-pin connector. More powerful video cards usually have a pair of connectors.

Continuing the topic of cable management, we can say with confidence that in some cases other power supply cables may not be needed at all. For example, if you are using M.2 drives in your system and are not installing various peripherals (such as an optical drive). In this case, you only need to power the motherboard and video card from the PSU. NVMe SSDs that are installed on a board and do not require additional connectors have long been recommended in most Computer of the Month builds.

However, any power supply will support a minimum of four SATA devices. And also the set includes MOLEX wires, which are now used in few places. In cheap cases, they can be powered, for example, by fans. In principle, video cards can also be powered through adapters from MOLEX (but I strongly advise against doing this in the case of expensive 3D accelerators!).

In especially neglected cases, when it is necessary to connect a large number of wires, it is better to take a partially or completely modular power supply unit. This approach will make life much easier when assembling the system. It's funny, but if only three or four wires are required from the power supply, then in this case it is also better to use a device with modular cable management - so that the extra "tail" does not stick out and does not interfere.

And yet, aesthetically speaking, assembling a system with a non-modular power supply is not a tragedy. Extra wires can be easily hidden under the hard drive cage. And even now, even the most inexpensive cases are equipped with a curtain (metal or plastic) on the bottom. It hides both the power supply itself and a heap of unused cords.

A fully modular power supply will be needed if you want to not only build a neat PC, but do it beautifully - using a braid, for example. The same Corsair sells sets of braided wires, or you can make a braid yourself.

A small announcement: I will tell (and show) in more detail about cable management in another article, which will soon be released on our website.

Cable length is another important performance parameter for any power supply. Of course, a lot depends on the computer case as well. But for most Midi-Tower models ranging in height from 400 to 500 mm with a bottom-mounted PSU, a 4/8-pin CPU power cable is 500-550 mm long. For Full / Ultra Tower with a height of 600-800 mm - you need at least 600 mm. It turns out to be a fairly simple rule: The length of the EPS cord should be equal to the height of the case, if we are talking about the lower location of the PSU... Then no surprises will happen during assembly. The length of the other power supply cables in the case of tower cases is of little interest to us. In some models, the length of the cord with a 24-pin port reaches 700 mm, in which case it is even more problematic to properly tuck it behind the case chassis.

An attentive reader must have noticed that I in no way touched upon the form factor of the power supply units themselves - they are different, sometimes a computer case. But this article is tied to the "Computer of the Month" heading, and it recommends assemblies in classic tower cases. I promise that I will devote a separate detailed article to the assembly of compact gaming PCs.

However, make sure your PSU fits into the case before purchasing. For example, the previously listed Corsair PSU models will fit 99% of Midi-Tower cases. But for some Corsair AX1200i with a length of 225 mm (and the connected wires will also take 50-100 mm), you will have to look for a more spacious computer "dwelling".

⇡ How much does a new power supply cost?

I will be brief in this section. Quite often, in the comments to "Computer of the Month" or to any other article related to power supplies, one has to observe a message in the style of " Why is there such a power supply unit? There is also enough model forN W". On the one hand, such commentators are right. On the other hand, the table below clearly shows that a lower power supply unit does not always cost significantly less than a model with a large number of declared watts. This rule is especially true for models with a power of 400-600 watts.

The cost of ATX form factor power supplies, rub.
		400-450 W	500-550 W	600-650 W	700-750 W	800-850 W	1000-1050 W
80 PLUS	Min.	2 850	2 940	3 560	3 850	No current models
	Max.	2 940	3 380	3 760	4 260
	Average	2 900	3 163	3 600	4 073
80 PLUS Bronze	Min.	3 090	3 420	4 500	4 800	7 080	No current models
	Max.	4 850	5 870	6 540	7 670	7 460
	Average	4 206	4 896	5 849	6 300	7 200
80 PLUS Silver	Min.	There are only two models in the store
	Max.
	Average
80 PLUS Gold	Min.	4 270	5 380	5 850	6 370	8 140	8 250
	Max.	6 190	10 850	10 760	12 270	1 3460	17 530
	Average	5 280	7 547	7 780	8 636	10 560	12 738
80 PLUS Platinum	Min.	No current models	8 840	10 930	10 800	12 440	12 470
	Max.		11 250	13 420	15 420	17 620	20 860
	Average		10 500	12 392	13 255	14 088	15 653
80 PLUS Titanium	Min.	No current models		15 560	17 700	17 870	19 690
	Max.			19 900	18 750	20 230	25 540
	Average			17 730	18 215	19 050	22 615

We see that more powerful devices of a similar class (for example, those with the 80 PLUS Bronze certification), if they cost more, then very little. Comparing average prices, we see that the difference between 400-450 W and 500-550 W power supplies is a little more than 600 rubles. In this situation, it is definitely worth paying this amount, but getting a more powerful device in return. The difference in price between 600-650 and 700-750 W units turns out to be even less.

And such comparisons, looking at the table, you can make a fairly large number. And therefore another question arises: if there is an opportunity for the same or a slightly larger amount to take a power supply unit of higher power, then why not use it? The question, however, is rhetorical.

To collect statistics, I went to the Regard store website, chose six popular manufacturers and calculated the average cost of power supplies of a certain power and a certain 80 PLUS standard.

⇡ Methodology and stand

In today's testing, a large amount of computer hardware was used to show how much power real-life gaming systems consume. In this regard, I relied on assemblies of the "Computer of the Month" section. A complete list of all components is shown in the table below.

Test bench, software and auxiliary equipment
CPU	Intel Core i9-9900K Intel Core i7-9700K Intel Core i5-9600K Intel Core i5-9500F AMD Ryzen 5 1600 AMD Ryzen 5 2600X AMD Ryzen 7 2700X
Cooling	NZXT KRAKEN X62
Motherboard	ASUS ROG MAXIMUS XI FORMULA ASUS ROG STRIX B450-I GAMING
RAM	G.Skill Trident Z F4-3200C14D-32GTZ, DDR4-3200, 32 GB Samsung M378A1G43EB-CRC, DDR4-2400, 16 GB
Video card	2 × ASUS ROG Strix GeForce RTX 2080 Ti OC ASUS Radeon VII ASUS DUAL-RTX2070-O8G NVIDIA GeForce RTX 2060 Founders Edition ASUS ROG-STRIX-RX570-4G-GAMING AMD Radeon RX Vega 64 ASUS PH-GTX1660-6G
Storage device	Samsung 970 PRO MZ-V7P1T0BW
Power Supply	Corsair CX450 Corsair CX650 Corsair TX650M Corsair RM850x Corsair AX1000
Frame	Open test bench
Monitor	NEC EA244UHD
Operating system	Windows 10 Pro x64 1903
Software for video cards
NVIDIA	431.60
AMD	19.07.2005
Additional software
Removing drivers	Display Driver Uninstaller 17.0.6.1
FPS measurement	Fraps 3.5.99
	FRAFS Bench Viewer
	Action! 2.8.2
Overclocking and monitoring	GPU-Z 1.19.0
	MSI Afterburner 4.6.0
Optional equipment
Thermal imager	Fluke Ti400
Sound level meter	Mastech MS6708
Wattmeter	watts up? PRO

Test benches were loaded with the following software:

• Prime95 29.8- Small FFT test, which maximizes the load on the central processor. This is a very resource-intensive application, in most cases, programs that use all cores are not able to load the chips more.
• AdobePremierPro 2019- rendering of 4K video by means of the central processor. An example of resource-intensive software that uses all processor cores, as well as available reserves of RAM and storage.
• "The Witcher 3: Wild Hunt"- testing was conducted in full screen mode in 4K resolution using maximum graphics quality settings. This game puts a heavy load on not only the video card (even two RTX 2080 Ti in the SLI array are 95% loaded), but also the central processor. As a result, the system unit is loaded more strongly than, for example, using FurMark synthetics.
• "The Witcher 3: Wild Hunt" +Prime95 29.8(Small FFT test) - a test for the maximum power consumption of the system when both CPU and GPU are loaded at 100%. And yet, it should not be ruled out that there are more resource-intensive bundles.

Energy consumption was measured using a watts up? PRO - despite such a comical name, the device can be connected to a computer, and with the help of special software it allows you to monitor its various parameters. So, the graphs below will show the average and maximum power consumption levels of the entire system.

The period of each power measurement was 10 minutes.

⇡ What power is needed for a modern gaming PC

I will note again: this article is to a certain extent tied to the "Computer of the Month" section. Therefore, if you dropped by to see us for the first time, then I recommend that you familiarize yourself with at least. In each "Computer of the Month" six assemblies are considered - mostly games. I have used similar systems for this article. Let's get acquainted:

• A bundle of Ryzen 5 1600 + Radeon RX 570 + 16 GB of RAM is an analogue of the starting assembly (35,000-37,000 rubles per system unit, excluding the cost of software).
• A bundle of Ryzen 5 2600X + GeForce GTX 1660 + 16 GB of RAM is an analogue of the basic assembly (50,000-55,000 rubles).
• A bundle of Core i5-9500F + GeForce RTX 2060 + 16 GB of RAM is an analogue of the optimal assembly (70,000-75,000 rubles).
• A bundle of Core i5-9600K + GeForce RTX 2060 + 16 GB of RAM is another option for the optimal assembly.
• A bundle of Ryzen 7 2700X + GeForce RTX 2070 + 16 GB of RAM is an analogue of an advanced assembly (100,000 rubles).
• A bundle of Ryzen 7 2700X + Radeon VII + 32 GB of RAM is an analogue of the maximum assembly (130,000-140,000 rubles).
• A bundle of Core i7-9700K + Radeon VII + 32 GB of RAM is another option for the maximum build.
• A bundle of Core i9-9900K + GeForce RTX 2080 Ti + 32 GB of RAM is an analogue of an extreme assembly (220,000-235,000 rubles).

Unfortunately, I could not get the Ryzen 3000 processors at the time of all the tests, but the results obtained from this will not become less useful. The same Ryzen 9 3900X, consumes less Core i9-9900K - it turns out that in the framework of an extreme assembly, it will be even more interesting and important to study the power consumption of an 8-core Intel.

And also, as you may have noticed, the article uses only mainstream platforms, namely AMD AM4 and Intel LGA1151-v2. I didn't use HEDT systems like TR4 and LGA2066. First, we have long since abandoned them in Computer of the Month. Secondly, with the appearance in the mass segment of the 12-core Ryzen 9 3900X and in anticipation of the imminent release of the 16-core Ryzen 9 3950X, such systems have become painfully highly specialized. Thirdly, because the Core i9-9900K still gives everyone a light in terms of energy consumption, once again proving that the calculated thermal power declared by the manufacturer says little to the consumer.

Now let's move on to the test results.

To be honest, the test results in programs such as Prime95 and Adobe Premier Pro 2019, I cite more for your information - for those who do not play and do not use discrete graphics cards. You can safely focus on this data. Basically, here we are interested in the behavior of test systems in loads close to maximum.

And here are very interesting things. In general, we see that all considered systems do not consume very much energy. The most gluttonous, which is quite logical, was the system with Core i9-9900K and GeForce RTX 2080 Ti, but even in stock (read - without overclocking) consumes 338 W when it comes to games, and 468 W - at maximum PC load. It turns out that such a system will have enough power supply for an honest 500 watts. It is so?

⇡ It's not just about watts

It would seem that this is the end of the article: recommend everyone a power supply with a capacity of 500 honest watts - and live in peace. However, let's do some additional experimentation to get a complete picture of what's going on with your PC.

In the screenshot above, we see that the power supplies work as efficiently as possible at 50% load, that is, half of the declared power. It may seem to some that the difference between a device with a basic 80 PLUS certification with an efficiency at the peak of about 85% in a 230 V network and, say, a "platinum" PSU with an efficiency of about 94% is not so great, but this is a delusion. my colleague Dmitry Vasiliev points out quite accurately: “A source of energy with an efficiency of 85% uselessly spends 15% of its power on heating the ambient air, while only 6% of the power is converted into heat by the“ breadwinner ”with an efficiency of 94%. It turns out that the difference is not “ some there"10%, but x2.5". Obviously, in such conditions, a more efficient power supply is quieter (it makes no sense for the manufacturer to adjust the fan of the device to the maximum rotational speed), and it heats up less.

And here is the proof of the above words.

The graphs above show the efficiency of some power supplies participating in the tests, as well as the rotational speed of their fans at different degrees of load. Unfortunately, the equipment used does not allow us to accurately measure the noise level, but by the number of revolutions per minute of the built-in fans, we can judge how noisy the power supply will be. It should be noted here that this does not mean at all that under load the PSU will stand out “from the crowd”. Still, usually the noisiest components of a gaming computer are the CPU cooler and graphics card.

Practice, as you can see, converges with theory. The power supplies do work at their maximum efficiency at about 50 percent load. Moreover, in this regard, I would like to note the Corsair AX1000 model - this power supply reaches its peak efficiency with a power of 300 W, and then its efficiency does not fall below 92%. But other Corsair blocks on the charts have the expected "hump".

At the same time, the Corsair AX1000 can operate in a semi-passive mode. Only at a load of 400 W does its fan start spinning at a frequency of ~ 750 rpm. The RM850x has the same characteristics, but in it the impeller starts to rotate at a power of ~ 200 W.

Now let's take a look at the temperatures. To do this, I disassembled all the power supplies. The fans from the top cover were removed and installed on a homemade tripod so that the distance between it and the rest of the PSU was about 10 cm. I'm sure the device did not work worse in terms of cooling, but this design allowed me to take pictures with a thermal imager. In the graph above, "Temperature 1" refers to the maximum temperature of the power supply inside when the fan is running. "Temperature 2" is the maximum heating of the PSU ... without additional cooling. Please do not repeat such experiments at home on your equipment! However, such a bold move allows you to clearly show how the power supply heats up and how its temperature depends on the rated power, build quality and the used component base.

Heating the CX450 to 117 degrees Celsius is quite a logical phenomenon, because this power supply operates at a load of 400 W at almost maximum, and even does not cool down in any way. The fact that the power supply has passed this test at all is an excellent sign. Here is a high quality budget model.

Comparing the results of other power supplies, we can come to the conclusion that they seem quite logical: yes, the Corsair CX450 model heats the most, and the RM850x least of all. At the same time, the difference in the maximum heating rates is 42 degrees Celsius.

It is important here to define the concept of “honest power”. Here is the Corsair CX450 model on the 12-volt line can transfer 449 watts of power. It is this parameter that must be looked at when choosing a device, because there are models that do not work as efficiently. In cheaper units of similar power, noticeably fewer watts can be transmitted over a 12-volt line. It comes to the point that the manufacturer claims support for 450 watts, but in fact it is only about 320-360 watts. So let's write it down: when choosing a power supply, you need to look, among other things, at how many watts the device gives out on a 12-volt line.

Let's compare the Corsair TX650M and CX650, which have the same power rating but are certified to different 80PLUS gold and bronze standards respectively. I think the images of the thermal imager attached above speak more eloquently than any words. Really, support for a specific standard 80PLUS indirectly speaks about the quality of the element base of the power supply... The higher the certificate class, the better the power supply.

It is important to note here that the Corsair TX650M transmits up to 612 watts over the 12-volt line, and the CX650 up to 648 watts.

Above in the pictures you can compare the heating of the RM850x and AX1000 models, but already at a load of 600 watts. Here, too, there is an obvious difference in temperatures. Overall, we can see that Corsair PSUs do a good job of handling the load they put on them - and even in stressful situations. At the same time, I think it is now clear why the graph above did not show the temperature of the AX1000 - it does not heat up much, even if the cover with the fan is removed from it.

Considering the results obtained, you can see that it is completely unreasonable to use a power supply in the system with a power twice the maximum power of the PC itself. In this operating mode, the power supply unit heats up less and makes noise - these are facts that we have just proved once again. It turns out that a power supply unit with an honest power of 450 W is suitable for a starting assembly, for a basic one - 500 W, for an optimal one - 500 W, for an advanced one - 600 W, for a maximum one - 800 W, and for an extreme one - 1000 W. Plus, in the first part of the article, we found out that there is not such a big difference in price between power supplies, the declared power of which differs by 100-200 watts.

However, let's not rush to final conclusions.

⇡ A few words about the upgrade

The assemblies in "Computer of the Month" are designed not only to work in the default mode. In each issue I talk about the overclocking possibilities of some components (or about the senselessness of overclocking in the case of some processors, memory and video cards), as well as the possibilities of the subsequent upgrade. There is an axiom: the cheaper the system unit, the more compromises it has... Compromises that will allow you to use a PC here and now, but the desire to get something more productive, quiet, efficient, beautiful or comfortable (necessary - emphasize) will not leave you anyway. Captain Evidence suggests that in such situations, a power supply unit with a good margin of watts is very useful.

Let me give you an illustrative example of upgrading the starting assembly.

I took the AM4 platform. 6-core Ryzen 5 1600, Radeon RX 570 and 16GB DDR4-3000 RAM were recommended. Even with a stock cooler (a cooling system that comes with the CPU), our chip can be easily overclocked to 3.8 GHz. Let's say I did something radical and changed the CO for a much more efficient model, which allowed me to raise the frequency from 3.3 to 4.0 GHz while loading all six cores. To do this, I needed to raise the voltage to 1.39 V, and also set the fourth level of Load-Line Calibration of the motherboard. This overclocking essentially turned my Ryzen 5 1600 into a Ryzen 5 2600X.

Let's say I bought a Radeon RX Vega 64 video card - on the Computeruniverse website a month ago it could be taken for 17,000 rubles (excluding shipping), and even cheaper from hands. And in the comments to "Computer of the Month" they talk so sweetly about used GeForce GTX 1080 Ti, sold for 25-30 thousand rubles ...

Finally, instead of the Ryzen 5 1600, you can take the Ryzen 2700X, which has significantly dropped in price after the release of the third-generation AMD family of chips. There is no particular need to disperse it. As a result, we see that in both cases of the upgrade I proposed, the power consumption of the system has more than doubled!

This is just an example, and the actors in the described situation may be completely different. However, this example, in my opinion, clearly shows that even in the starting assembly, a power supply with an honest power of 500 W, or even better 600 W, does not interfere at all.

⇡ "Gaming PCs do not need 1 kW units" - commentators under the articles on the site

Such comments are often seen when it comes to gaming PCs. In the vast majority of cases - and we found it out in practice - this is how it is. However, in 2019 there is a system that is able to impress with its power consumption.

We are, of course, talking about an extreme assembly in its, so to speak, maximum combat form. Not so long ago, an article "" was published on our site - in it we talked in detail about the performance of a pair of the fastest GeForce video cards in 4K and 8K resolutions. The system is fast, but the components are selected in such a way that it is very easy to make it even faster. In addition, it turned out that overclocking the Core i9-9900K to 5.2 GHz turns out to be completely useful in the case of the GeForce RTX 2080 Ti SLI array and Ultra HD games. Only at its peak, as we can see, such an overclocked configuration consumes more than 800 watts. Therefore, for such a system in such conditions, a kilowatt power supply will definitely not be superfluous.

⇡ Conclusions

If you have carefully read the article, then you have identified for yourself several main points that you need to keep in mind when choosing a power supply. Let's list them all again:

• unfortunately, it is impossible to focus on the TDP indicators declared by the manufacturer of the video card or processor;
• the power consumption of computer equipment does not change much from year to year and is within certain limits - therefore, a high-quality power supply purchased now will last a long time and faithfully and will definitely come in handy during the assembly of the next system;
• the needs for cable management of the system unit also affect the choice of a power supply unit of a certain power;
• not all power connectors on the motherboard need to be used;
• the power supply unit of lower power is not always more profitable (in terms of price) than a more powerful model;
• when choosing a power supply, one must look at how many watts the device gives out on a 12-volt line;
• support for a certain standard 80 PLUS indirectly speaks of the quality of the element base of the power supply;
• it is completely unwise to use a power supply whose honest power is twice (or even more) the maximum power consumption of the computer.

Quite often you can hear the phrase: “ More is not less". This very laconic aphorism perfectly describes the situation when choosing a power supply. Take a model with a good power reserve for your new PC - it certainly won't be worse, but in most cases it will only be better. Even for an inexpensive gaming system unit, which consumes about 220-250 W at maximum load, it still makes sense to take a good model with an honest 600-650 W. Because a block like this:

• will work quieter, and in the case of some models - absolutely silent;
• it will be colder;
• will be more efficient;
• will allow you to easily overclock the system, increasing the performance of the central processor, video card and RAM;
• will allow you to easily upgrade the main components of the system;
• will survive several upgrades, and also (if the power supply is really good) will settle in the second or third system unit;
• will also allow you to save money during the subsequent assembly of the system unit.

I think very few readers will refuse a good power supply. It is clear that it is not always possible to immediately buy a high-quality device with a large reserve for the future. Sometimes, when buying a new system unit and a limited budget, you want to take a more powerful processor, and faster video cards, and a higher-capacity SSD - all this is understandable. But if you have the opportunity to buy a good power supply with a margin, you don't need to save on it.

We express our gratitude to the companiesASUS andCorsair, as well as the computer store "Regard" for the equipment provided for testing.

A power supply for a stationary computer is a necessary thing in the realities of the situation with electricity in the countries of the former CIS: frequent voltage drops and periodic blackouts. Let's see how it works, how to check the power supply and what to do if it beeps?

What is a power supply?

A computer power supply is a device that generates the voltage that is necessary for the normal operation of a computer, converting the current that enters it from the general electrical network. In Russia, the device is made from alternating current from a general electrical network of 220V and a frequency of 50Hz into several indicators of direct current of low values: 3.3V; 5B; 12V, etc.

The main thing to look at when buying an electrical appliance is its power, which is measured in watts (W). The more power the computer consumes, the more power should be in the power supply.

Low-end computers, which are often bought for office or school equipment, consume about 300-500 watts. If the model is not cheap - gaming or for working with heavy engineering or installation programs, then the power of such a computer is about 600 watts. In addition, there are models that need power per kilowatt, but these are computers with top-class video cards that the average user rarely has.

The power supply acts as the energy core of a stationary computer, because it is he who supplies voltage to all components of the computer and allows the computer to continue working and not get lost due to current surges. First, the power supply is connected to the public network through an outlet, and then it is connected to the computer. It distributes the voltage that a particular part requires across the entire PC.

Usually, a lot of cables go from a computer power supply to the PC itself: to the motherboard, hard drive, video card, drive, to the fan, etc. The better and better the unit, the more stable it reacts to the fact that a voltage drop occurs in the general network. Exactly the fact that the power supply always delivers constant voltage, regardless of what is going on in the general network and keeps the stationary computer and its individual components from breakdowns and wear and tear.

If the computer has even the best video card, motherboard and a modern cooling system, and the power supply does not cope with the task set before it, then all the power of the components is useless.

What is the danger of a lack of power in a PC?

If you are undecided about whether to take a sufficiently powerful computer power supply, then here are some examples of what happens when the power of the power supply is insufficient:

• The hard disk may be damaged or partially damaged. If it doesn’t get enough power, the readheads don’t work at full capacity, slide over the surface of the hard drive and scratch it. Interestingly, scratching sounds can be heard.
• There may be problems with the video card. In some cases, the monitor even disappears. This is especially the case if a heavy game is running.
• Also, removable drives may not be recognized by the computer if there is no normal power supply.
• When the PC is running at full power, it can shutdown and reboot itself.

However, do not think that all the problems are only in the power supply. If there are bad components, then the problem is most likely in them. However, if everything is fine with spare parts, then it is worth buying a more powerful power supply unit - and all problems will go away.

The difference between a bad power supply and a good one

How do you know which power supply you have, good or not powerful enough? There are several criteria by which a high-quality power supply is determined:

1. Good protects against power surges in the general network. If a strong surge occurs, the power supply will burn itself out, but leave the computer and components unharmed.
2. A good power supply has a convenient wiring system, it is modern, it is possible to connect and disconnect some cables yourself.
3. The high-quality model has a good cooling system, it does not overheat, the PSU fan does not make much noise during operation.

Checking the power supply

Sometimes it happens that the computer does not work well, does not turn on or turns off by itself, then you need to check the power supply. There is a way how you can do this at home on your own without a multimeter reconnecting circuits.

Staple method

There is an easy way to check if the power supply is working properly with a simple paper clip. This is a simple method that will not show if the power supply is working normally, but it is easy to use it to understand if the device is supplying current to the computer as a whole. The sequence of actions is as follows:

• Disconnect the computer from power.
• Open the case cover and disconnect the connector from the motherboard.
• From a paper clip, make a U-shaped jumper and jumper short the green connector wire and the black wire that runs next to the green one.
• Turn on the power supply.
• If everything worked, then in theory the power supply works fine. If not, then it should be carried for repair.

The main symptoms and malfunctions

How can you tell if a power supply needs a thorough inspection and repair in a service or is it working well? If the power supply unit is completely out of order, it will not turn on with a jumper, but sometimes there are problems that you just do not notice.

Most often this happens if the user notices that there are some irregularities in the operation of the motherboard or in RAM. In fact, this may be a problem with the power of the PSU and with how regularly and without interruptions it supplies it to certain microcircuits. The problems described below may occur to the user if the power supply is faulty.

If you notice one of these symptoms and suspect that the problem may be with the power supply, as it is old or cheap, then you need to bring it to the repair, as it can be dangerous for the computer. Often, the PCs simply burned from the fact that the power supply unit was faulty or not working well. However, if there are few reasons to doubt the reliability of the power supply unit, then it is worth calling a specialist to carry out a comprehensive check of all computer systems, make the necessary cleaning and check the power supply itself. Remember that checking and repairing will be cheaper than buying a new computer, besides, a timely consultation will help save a lot of nerves and extend the life of the device for several more years beyond the period measured for it.

Feeds the power supply

It is worth investigating in more detail the problem of the power supply squeak, since this is one of the most common reasons why users turn to the service. This is not only an annoying symptom, but also a serious reason to think about repairing or buying a new device.

There are several reasons why the power supply beeps:

1. The reason is electricity. If there are strong voltage drops, they knock down the coordinated work of the power supply and this is manifested by an unpleasant squeak. However, it is most often one-time, does not last long, does not repeat more than a couple of times a week (unless there are serious voltage problems in your house, from which the lights often go out and all household appliances suffer). The problem most often ends up in the outlet. In order to check this, it is worth connecting the device to a new outlet, preferably on the opposite side of the room and making sure that the power supply does not beep as often as before.
2. A frequent squeak that lasts longer than a couple of seconds is a more disturbing call, because it speaks of a malfunction inside the power supply itself. This is most often the case when the connections of the internal components are weakened.
3. In addition, a squeak may indicate errors in the assembly of the power supply. However, in this case, the PSU will have a frequent and unpleasant squeak right after the purchase. If you contact the service center with a check, they will change it or rebuild it for you so that there is no malfunction.
4. Please note that if the squeak is frequent, it does not go away when you connect it to another network, and the power supply is very hot and noisy, it urgently needs to be carried for repair. In addition, the bloating of the PSU case is an alarming signal - then you need to change it as soon as possible. And remember that buying a new power supply or fixing an old one is cheaper than a new computer and data that will burn along with the hard drive if there is a sudden power surge.

The power supply is an essential component of any personal computer, on which the reliability and stability of your assembly depends. There is a fairly large selection of products from various manufacturers on the market. Each of them has two or three lines and more, which include a dozen more models, which seriously confuses buyers. Many do not pay due attention to this issue, which is why they often overpay for excess capacity and unnecessary "bells and whistles". In this article, we will figure out which power supply is best for your PC?

A power supply (hereinafter referred to as PSU) is a device that converts high voltage 220 V from an outlet into values ​​digestible for a computer and is equipped with the necessary set of connectors for connecting components. It seems to be nothing complicated, but after opening the catalog, the buyer is faced with a huge number of different models with a bunch of often incomprehensible characteristics. Before talking about the choice of specific models, let's take a look at what characteristics are key and what should be paid attention to in the first place.

Main parameters.

1. Form factor... In order for the power supply to fit corny into your case, you must decide on the form factors, based on from the parameters of the case of the system unit itself ... The PSU dimensions in width, height and depth depend on the form factor. Most come in the ATX form factor for standard cases. In small system units of the microATX, FlexATX standard, desktops and others, units of smaller sizes such as SFX, Flex-ATX and TFX are installed.

The required form factor is spelled out in the characteristics of the case, and it is by it that you need to navigate when choosing a power supply.

2. Power. The power depends on what components you can install in your computer, and in what quantity.

It's important to know! The figure on the power supply is the total power across all its voltage lines. Since the main consumers of electricity in a computer are the central processor and a video card, the main power line is 12 V, when there is still 3.3 V and 5 V to power some of the nodes of the motherboard, components in the expansion slots, power drives and USB ports. The power consumption of any computer on the 3.3 and 5 V lines is insignificant, therefore, when choosing a power supply unit in terms of power, you should always look at the characteristics " power on the 12 V line", which ideally should be as close as possible to the total power.

3. Connectors for connecting accessories, the number and set of which depends on whether you can, for example, power a multiprocessor configuration, connect a couple or more video cards, install a dozen hard drives, and so on.

Main connectors, except ATX 24 pin, this is:

To power the processor, these are 4 pin or 8 pin connectors (the latter can be collapsible and have a 4 + 4 pin record).

To power the video card - 6 pin or 8 pin connectors (8 pin is most often collapsible and is designated 6 + 2 pin).

For connecting 15-pin SATA drives

Additional:

4pin MOLEX type for connecting outdated HDDs with IDE interface, similar disk drives and various optional accessories such as reobases, fans, etc.

4-pin Floppy - for connecting floppy drives. It is a rarity these days, so these connectors most often come in the form of adapters with MOLEX.

Extra options

Additional characteristics are not as critical as the main ones, in the question: "Will this PSU work with my PC?", But they are also key when choosing. affect the efficiency of the unit, its noise level and ease of connection.

1. Certificate 80 PLUS determines the efficiency of the power supply unit, its efficiency (efficiency). List of certificates 80 PLUS:

They can be divided into basic 80 PLUS, the far left (white), and colored 80 PLUS, ranging from Bronze to the top Titanium.

What is efficiency? Let's say we are dealing with a unit whose efficiency is 80% at maximum load. This means that at maximum power, the PSU will consume 20% more energy from the outlet, and all this energy will be converted into heat.

Remember one simple rule: the higher the 80 PLUS certificate in the hierarchy, the higher the efficiency, which means it will consume less excess electricity, heat less, and often make less noise.

In order to achieve the best efficiency and obtain the "color" 80 PLUS certificate, especially the highest level, manufacturers use their entire arsenal of technologies, the most efficient circuitry and semiconductor components with the lowest possible losses. Therefore, the 80 PLUS badge on the case also speaks of the high reliability, durability of the power supply, as well as a serious approach to creating the product as a whole.

2. Type of cooling system. Low level of heat dissipation of power supplies with high efficiency, allows the use of silent cooling systems. These are passive (where there is no fan at all), or semi-passive systems in which the fan does not rotate at low powers, and starts working when the power supply unit becomes "hot" in the load.

When choosing a power supply unit, you should pay attention and by the length of cables, main ATX24 pin and CPU power cable when installed in a case with a bottom-mounted power supply.

For optimal routing of the supply cables behind the rear wall, they should be at least 60-65 cm long, depending on the size of the enclosure. Be sure to take this point into account so that you do not mess with extension cords later.

You need to pay attention to the number of MOLEX only if you are looking for a replacement for your old and antediluvian system unit with IDE drives and drives, and even in a solid amount, because even the simplest PSUs have at least a couple of old MOLEX, and in more expensive models there are dozens of them.

I hope this small guide to the catalog of the DNS company will help you in such a difficult issue at the initial stage of your acquaintance with power supplies. Enjoy the shopping!