Motherboard formats. Modern forms Factors or sizes of motherboards for PC

(System Board), sometimes called Motherboard, Main or Main Board (Main Board); All these terms are interchangeable. Almost all internal components personal computer inserted into the motherboard, and it is its characteristics that determine the capabilities of the computer, not to mention it overall productivity. In this chapter, we will look at the main types of motherboards, their components and interface connectors.

There are several of the most common form factor taken into account when developing motherboards. The form factor (Form Factor) defines the physical parameters of the board and the type of the housing in which it can be installed. System boards form factor may be standard (i.e. interchangeable) and non-standard. Non-standard form factor, unfortunately, are an obstacle to upgrading the computer, therefore it is better to refuse them. The most famous form factories of the system boards are listed below.

Over the past few years, there has been a transition from the original Baby-AT formator system cards, which was used in the first IBM PC and XT computers, to the BTX and ATX form factor, used in most full-size desktop and vertical systems. There are several ATX form factor options, including Microatx (reduced version of the ATX form factor used in small size systems) and FlexATX (even more reduced option designed for low price level computers). The BTX form factor involves changing the position of the main components in order to improve the cooling of the system, as well as the use of the thermal module. There are reduced variants of this form factor - Microbtx and Picobtx. There are also other compact form factor, such as DTX and MINI-ITX, which is a reduced version of FlexATX. The NLX form factor was designed for corporate desktop systems, but over time, the FlexATX form factor was displaced. The WTX form factor was developed for workstations and medium loading servers, but did not receive widespread. Modern form factor and their applications are presented in the table below.

Despite the widespread Baby-AT boards, full-size AT and LPX, they came to shift system fees More modern form factor. Modern formators are actually an industrial standard that guarantees the compatibility of each type of boards. This means that the ATX motherboard can be replaced by another board of the same type, another BTX board can be used instead of the BTX system board, etc. Thanks to optional functional features Modern system boards The computer industry was able to quickly go to new form factor. Therefore, it is strongly recommended to acquire systems created on the basis of one of the modern form factor.

To system charges, the parameters of which do not fit into any of the forms of the industrial standard, should be treated as non-removable. Buy computers with non-standard system boards follows only in the case of special circumstances. Repair and modernization of such systems is quite expensive, which is due, first of all, with the impossibility of replacing systemics, housing or power sources by other models. Independent form factor systems are sometimes called a "disposable" PC, which becomes apparent when the time of their upgrades or repair comes after the end of the warranty period.

Attention!
Currently, '' disposable '' PCs are more common than ever. According to some estimates, their share accounts for over 60% of the computers sold. This is connected not so much with the boards used (FlexATX and MicroAtx system boards today are used more often than the LPX preceding models), but with miniature SFX power sources and narrow Micro-Tower enclosures that occupy a privileged position in the modern PC market. Cheap systems using a small housing and a small power source, in principle, are more suitable for upgrading compared to previous models. But if you need another extension connector or, for example, an additional drive, then you are in a literal sense, it is limp to the wall. Mini-Tower systems are quite crowded and limited, so soon I believe, go into the discharge '' disposable '', like the LPX systems displaced.

Be especially careful with the recently emerged industrial standard systems, which include, for example, Dell computers, released since 1996 to the present. These computers use a modified power supply and modified ATX board power connectors, which makes these components absolutely not compatible with standard system boards and power supplies. Therefore, in order to upgrade the power supply, you will have to use a special dell-compatible block. Moreover, replacing the standard motherboard, it will be necessary to purchase the appropriate power source and, maybe even the housing.

So, if you want to get a really expandable system, stay on the computer with system board ATX or BTX and MID-Tower (or more) housing, having at least five compartments for installing drives.

In any case, in which you can install a full-sized AT system board, you can install the Baby-AT system board. A huge amount of Baby-AT formation boards for PCs equipped with processors of almost all types - from the first 8088 to Pentium III or Athlon; True, installation modern processors Presented a very difficult task. As you can see, Baby-At system boards were produced long enough. Despite the fact that the standard Baby-AT (Fig. 1) is already outdated, the ATX standard has completely inherited his philosophy of interchangeability. In fig. 2 is an example of a fairly modern Baby-AT system board containing USB, SIMM and DIMM connectors, as well as an ATX power supply connector.

The easiest way to identify the Baby-AT system is to look at the rear panel of the case. Expansion boards are inserted directly into the connectors on the system board and are oriented at an angle of 90 ° relative to it; In other words, extension boards are located perpendicular to the motherboard. At the same time, only one connector is noticeable on the back panel of the Baby-AT system board - 5-pin DIN, designed to connect the keyboard; True, it should be noted that some Baby-AT class systems have been equipped with 6-pin MINI-DIN connectors of a smaller size (these connectors are often called PS / 2) and even the mouse connector. All other connectors were placed or directly on the system board, or on remote blocks that are connected to the system board with cables. The keyboard connector is visible through the hole in the housing.

Picture 1

Figure 2.

All Baby-AT motherboards correspond to a number of requirements for height, placement of mounting holes and connectors (including connector for connecting the keyboard), but may vary wide. System fees, the dimensions of which are less than standard 9 × 13 inches (22.86 × 33.02 cm), were often attributable to MINI-AT, Micro-AT form factor, and sometimes 2/3-Baby or 1/2-Baby. At the same time, they could be normally installed in the Baby-AT standard housing.

LPX and MINI-LPX boards were developed by Western Digital in 1987 for its computers. In the name "LPX", the reduction of LP is decrypted as a "low profile" (Low Profile). Since the connectors were located in such a way that all extension boards turned out to be parallel system board, it became possible to release low-profile enclosures, the dimensions of which are less than that of the Baby-AT class systems.

Although PC motherboards are no longer produced by Western Digital, their designs use some other manufacturers. Unfortunately, the full specifications never have been published; This is especially true for the position of the connectors to install the remote circuit boards. As a result, motherboards from different manufacturers turned out to be non-visible. Some suppliers, such as IBM and HP, offered LPX systems in which T-shaped output fees were used, which made it possible to arrange the expansion fees perpendicular to the motherboard, but still at a certain distance from it. Lack of standardization means that if your system is installed LPX, in most cases you will not be able to replace it with the LPX system board from another manufacturer. As a result, it is necessary to deal with the system, further modernization and repair of which are practically impossible. Therefore, I do not recommend purchasing LPX systems.

Similar "closed" architecture of systems of this standard at that time, few people interested, and these fees were very popular since the late 1980s until the mid-1990s. These were mainly the Compaq and Packard Bell production system, as well as some other companies that used LPX system boards in their entry-level systems. LPX system boards are most commonly used in low-profile housings, although they met in Tower type housings. As already noted, most often it was inexpensive systems sold in electronics supermarkets. Today, the LPX form factor considers it outdated.

LPX fees (see Figure below) differ significantly from the rest. For example, the expansion connectors in them are mounted on a separate remote board, which is inserted into the motherboard. Expansion cards are inserted into the remote fee, and their planes are parallel to the motherboard, which reduces the height of the computer case. Expansion connectors depending on the design can be located both on one and both sides of the remote board. Manufacturers used by TOWER enclosures sometimes used T-shaped output fees, which allowed the expansion connectors perpendicular to the motherboard, however, it is somewhat raised over it.

Another difference between the LPX boards lies in the characteristic location of the connectors on the rear panel - in one row. Meaning connectors for monitor VGA. (15 contacts) parallel port (25 contacts), two serial ports (9 contacts) and mini-din connectors for the PS / 2 keyboard and mouse. All these connectors are mounted on the board itself and after installation turn out to be located opposite the corresponding holes in the case. On some LPX system boards, additional built-in connectors are installed, for example for a network or SCSI adapter. Since LPX systems have been equipped with a high degree of integration, many manufacturers of system boards, enclosures and LPX systems often called their solutions "all in one".

LPX and MINI-LPX boards are shown in the figure below.

I am often asked how to recognize the presence in the LPX board system. For this you do not even need to disassemble the case. LPX system boards are distinguished by the fact that the tire slots in them are made on a separate board connected to the system, as in the case of the NLX form factor boards. Therefore, all its connectors are parallel to the motherboard. It is easy to determine by looking at the back side of the body. If all connectors are parallel to the motherboard, it means that the remote charge is used. This is a sure sign of LPX. In addition, in LPX all connectors are located below and are lined up in one line. All LPX system boards, regardless of the shape, size and placement of outputs, suggest the placement of all external ports at the rear edge of the board (see Figure below). At the same time, according to Baby-AT, connectors for serial and parallel ports, PS / 2 ports, and USB ports are used. At the same time, on ATX and BTX system boards, all external ports are grouped to the left of the expansion connectors.

As already noted, the remote board is also used in the NLX boards. But in LPX it is placed in the middle of the motherboard, and in the NLX side, and it is actually connected to the system board.

The figure below shows two typical examples of connectors on LPX system boards. Note that not all LPX boards are equipped with a built-in sound subsystem, so the corresponding connectors may be absent. In addition, maybe absent uSB ports (or other ports), although the total port location scheme is preserved. Connectors along the rear edge of the boards can "conflict" with tire connectors. That is why remote fees are used. The presence of embedded connectors is the undoubted advantage of LPX, and, unfortunately, it is devoid of Baby-AT fees. However, LPX boards are not standardized and not fully interchangeable, so choosing a LPX form factor cannot be called successful. New motherboards formators such as ATX, MicroATX and NLX have built-in connectors, and also follow some standard. The LPX design with a remote payment allowed the system designers to create small-sized computers, and this direction continued the new NLX formator. This form factor, in fact, was created as a modern LPX replacement.

The process of assembling a new stationary computer or an old upgrade is always accompanied by a non-small number of questions, the answers to which you need to get in a timely manner, that is, before buying expensive components. Therefore, at the PC configuration plan, the user, first of all, should determine which motherboard form factor will be applied in it. After all, it is he asks a bunch of parameters for the future assembly, ranging from the size of the case system Block Computer, ending with the type of cooling system built into it. Based on this, in this topic, we consider which form factors of motherboards, their types, formats, sizes, purpose, etc.

What is a motherboard form factor

Motherboard form factor is a standard installed by the manufacturers, specifying its overall and connecting dimensions, that is, the size of the mounting to the housing, the number and location of the interface slots for connecting random access memory, video cards, different types of extension cards, entering and output ports and other necessary interface connectors.

As you can see, this parameter does not directly affect how appearance In general, the collected system unit and its hardware stuffing. If you choose not the correct motherboard form factor, then the consequences may be sad, leading to unplanned budget consumption. Here you need to take into account the set of factors: this is the size of the system unit housing, its internal space for installing the extension cards, video card, processor, power supply, disk system, and cooling systems.

If the configuration is designed for powerful gaming computerThe latter of the listed items require special attention.

Overview of motherboard classifications Let's start with the most popular form factors in circles and ending the MP of the professional level intended for specific tasks.

Form factors of system boards for office and gaming PCs

ATX Form Factor

This format of MP is the most popular for building stationary computers Any configuration, ranging from an office version, ending with a powerful gaming station. ATX format boards have standard dimensions of 30.5x24.2 cm, which allows manufacturers to easily empower them with all the necessary functionality and a full-fledged complete base with slots, ports, interface connectors, power supply and so on.

To important constructive features This sizes of MP should be attributed to the fact that they are compatible only with the buildings of the system units of the same ATX standard. On the one hand, it seemed to be a minus, but on the other, the assembly of computers with their use can save money from the budget allocated to them.

First, the computer assembled on their base is less demanding on the cooling system, because the components of its hardware filling do not have to use in a small case, which means they have good ventilation without the use of expensive cooling systems.

Secondly, the segment of buildings compatible with the motherboards of the ATX form factor is greater than other sizes. Therefore, collecting a computer, the user does not have difficulty choosing the body of the future PC for the financial side of the issue or the choice of model.

MicroATX (MATX)

This sizes of motherboards is a trimmed version of the ATX standard. This concerns both sizes and a complete base. The dimensions of the MP of this standard are 24.4x24.4 cm. They are fully compatible with the enclosures of the previous format, but not vice versa. Often, MicroATX boards may be similar to configuration with their collections of the ATX standard. That is, they can be equipped with the same chipset, but with a smaller number of PCI slots designed to install various expansion cards.

In addition, not rare MP composer size MicroATX is equipped with a built-in graphic core, but there are no ATX configuration. It follows that system fees of this form factor are not targeted to build gaming SystemsAnd in most cases, oriented only to create office destination computers.

Flexatx

Flexatx form factor is the following evolution aside to reduce motherboards and cheapening computers collected on their base. MP this format They have a size of 22.9x19.1 cm and are intended only for office PCs. They, like their predecessors, are fully compatible with the buildings of the system units of ATX format and with their power system.

An important distinguishing feature of the MP of this standard, which allows them to achieve not a high selling cost, are their more scarce complete base. In some cases, they are not even completed with expansion slots, and the user has to be content only only by USB ports and IEEE-1394 / FireWire.

Below in the video, the main differences between the MP family of the ATX family and the highlights that should be paid attention to, collecting a new PC.

Motherboard formats for compact PC

DTX and MINI-DTX

DTX and MINI-DTX Form Factors, represented by AMD, are focused on building compact, quiet, energy-bearing and inexpensive computer multimedia systems HTPC. The dimensions of the MP of this sizes are 24.4x20.3 and 17x20.3 cm, respectively. They have full compatibility with the ATX standard on the size of the mount and on the power connectors.

The disadvantages of this standard include limited expansion capabilities due to the presence of only 2 slots - 1x PCI and 1X PCIE and the use of only low-profile cards, installed in these slots.

Mini-ITX

The format of MINI-ITX motherboards developed by Via Technologies is mechanically and electrically compatible with ATX Form Form. Their sizes are - 17x17 cm. Thanks to the use of embedded processors, SSD disks as file drives and the use of the passive cooling system this type MP aims to create inexpensive compact and quiet multimedia home systems.

The video shows below short review one of the MP form factor Mini-ITX where its advantages and possible scope are considered.

System boards formats for server systems

Extended ATX (EATX)

The dimensions of the MP form factor EATX are 30.5 × 33.0 cm. This standard is more applied to create servers, where the motherboard requires the installation of two or more processors, a large number of RAM and all sorts of expansion cards. The second name is SSI EEB.

SSI CeB.

SSI CEB form factor is focused on building workers of high-performance stations and server solutions. dimensions The motherboard boards of this standard are 30.5 × 25.9 cm.

As you can see, the classification of system boards is quite extensive and includes both obsolete species and newly developed. If they are divided into a similar principle, then the picture simplifies the reflecting reality will be as follows:

Outdated form factors: LPX, full-size AT, Baby-AT board; Mini-ATX.
Modern standards: ATX; microatx; FlexATX, EATX, WTX, NLX, CEB
Implemented Size: Mini-ITX, Nano-ITX, Pico-ITX, BTX, Microbtx, Picobtx, DTX and MINI-DTX

1. Interaction of motherboard and processor
2. Selection of socket "A
3. Tire frequency
4. Chipset.
5. Manufacturers
6. "Game" or "non-game" fee
7. Memory
8. Form factor board
9. Number of interfaces and connectors
10. Processor acceleration

The motherboard is the link link all other computer devices, and therefore the question is how to choose the motherboard - far from idle. The stability of the PC and its durability depends on the choice of motherboard, and we do not want to get into situations the need for frequent, expensive selection and iron updates, is not it?

In this material we will tell you what motherboards are, what parameters should pay attention to first of all how to choose a motherboard so that it fit to the processor and so on. First of all, it is worth asking for yourself the question: in which PC is a motherboard - office, game or mixed targets (home).

Motherboard and processor interaction

First of all, we must decide on the architecture of our future PC, namely to decide, on the basis of AMD or Intel, we will build our entire system.

Selection Socket'a

The socket is a view of the connector in the motherboard corresponding to the processor connector, it is he who divides all existing fees into two large categories:

Sockets starting on AM, FM and S support AMD processors;
Sockets starting on LGA have the support of Intel processors.

Thus, we understand that the choice of motherboard and the processor should occur simultaneously, and if you plan to use the motherboard longer than one processor generation, you will be forced to remain the right to choose the manufacturer of the processor. It is also worth noting that the motherboard can be equipped with more than one socket (but one type), but such solutions are usually preferred to create servers, not a PC for personal use.

Tire frequency

This section we are talking about a common bandwidth Devices, the higher the frequency - the greater the performance of the system, everything is obvious here. Recall that the frequency of the processor bus will also be coincided with the frequency of the motherboard bus, otherwise you will spend the money. Select devices that will show the greatest performance working in tandem.

Chipset

Everything is simple, chipset, he is the northern bridge - this is a combination of chips contained on the motherboard and protruding the link between the connected devices. The most popular manufacturers refer both the above mentioned AMD and Intel and the production aTI video cards and NVIDIA.

To the main modern intel chipsets relate:

B250 / H270 - for office, multimedia and gaming PCs;
Q270 - for the corporate sector;
Z270 - for powerful gaming and professional PCs;
X99 / x299 - for very powerful professional PCs.

The main modern AMD chipsets include:

A320 - for office and multimedia PCs;
B350 - for gaming and professional PCs;
X370 - for enthusiasts.

These chipsets have a lot of differences, but ultimately we are only interested in their target purpose. If we select your motherboard for a game computer, then stop at Z270 and B350, and so on. Pick up the motherboard. Knowing the final appointment of a collected computer will not be difficult even newcomer.

Manufacturers

This item is important if you have contradicts choosing a motherboard. The most expensive and most relevant in the high price segment are ASUS motherboards. If we look through the prism price / quality, especially if we are looking for a motherboard for games, you should pay attention to the MSI brand. In a more loyal to the buyer, the segment is not bad for the fee from Gigabyte and Asrock.

On the market maternal maps There are also less famous producers and name to them - Legion, but there are no so fierce battles around the motherboards as around processors or video cards, and therefore it is not worth overpaying for the name, the more unsuccessful models are found at market chadliners. In any case, it is worth remembering that the question of how to choose a motherboard, the answer should not begin with the manufacturer's name - it is secondary.

"Game" or "non-game" fee

In fact, the motherboard is not responsible for performance in the resource-intensive applications like demanding games, because this concept Very ephemery. If you insert four RAM strips on an expensive fee and repeat this process With cheaper, the result will not change.

Behind the appearance has to pay

The only difference is the potential of the card when the processor is accelerated, it is already worth a carefully to dwell on the board, its cooling, stability stability in acceleration and other secondary characteristics. In general, this will be said about this a few words in conclusion.

Memory

The number of slots depends on the motherboard form factor, because do not hope to put more than two slats into the motherboard compact format. Full-size motherboards will cope with four slots, and sometimes more. Relevant memory type on this moment is DDR4, but they differ in frequency. True, we do not advise you to chase the beautiful numbers above 3000 MHz, the price increase is exponential, but the increase in performance is not so large

This is not all the characteristics that distinguish good fee From weak, but they will be enough to not get into the unpleasant situation after the purchase.

Form factor board

The size of the board does not directly affect the size of the case of your computer, and, accordingly, in the place that it takes is, therefore it makes no sense to take the largest format - it will not necessarily be the most productive, but it will definitely be the most cumbersome.

Take a look more for available options:

E-ATX - size 305x330 mm. Paper data are presented under the LGA 2011-3 connector and, as can be seen from the dimensions, can become a headache in ergonomic matter. They are created under the top processors and are equipped with the most productive elements of cooling and nutrition. If the place occupied is not for you a headache - you can safely give them your preference.

Standard-ATX - 305x244mm. Perhaps the most widely presented format in the market, you will not have compatibility issues with other devices, but still, the board is quite cumbersome and is not suitable for compact solutions.

Micro-ATX - 244x244 mm. The reduction in the board height is achieved by reducing PCI-E slots. If earlier this form factor was perceived as budget analogue Larger payments, then with the development of electronics, it has become capable of realizing the entire functionality of the older brothers.

Mini-ITX - 170 × 170 mm-Warrant for amateurs Replace the standard computer case with something compact and stylized under multimedia player.

Mini-stx - 140 × 140 mm. Memory modules from external laptops are already used here and external power supplies. You can experiment with the assembly of a PC based on this board, but most likely will lose in performance and overpaid.

Number of interfaces and connectors

Often buyers choose a fee based on the name of the manufacturer or the mythical term "game", but come home to discover that they can simply be connected to it. In order not to have a similar incident happened to you, we will try to briefly interview all the external interfaces for the motherboard.

First you need to decide how much USB outputs you need on the rear panel for connecting peripheral devices. It should not be chased by quantity, but reasonable 4-6 ports should be present. It is desirable that a couple of them correspond to the standard 3.0, then you will not have trouble with portable connectivity hard disks. Slowly in our life includes a format 3.1 - look behind the horizon of events and to take care of its presence, it would be nice.

SATA is another necessary connector, high-speed SSDs work with this interface, the benefit of this connector is an integral part of any, even the most budget motherboard.

Tip from my own experience - be sure to consider the presence of a built-in Wi-Fi adapter. The router is already almost in every home and it is much easier to purchase a suitable fee, rather than engage in the time-consuming process of cable laying to your computer and spoil the appearance of the room.

If you are an audiophil and sound quality for you, please note whether the integrated sound card system supports 5.1 and 7.1 or immediately ask to add a suitable discrete audio card to your motherboard.

PCI-Express slots and their location is not as critical for gamers choosing one top card, but if you pursue other goals and want to use SLI / CrossFire technologies, then take a look at the number of ports and the comfort of their location - it will not be superfluous.

Processor acceleration

If your motherboard is a base for overclocking the processor, then you need to immediately cope with the previous experience of the owners of this board, in order to achieve the maximum result and increase productivity as much as possible. If you are looking for an "overlocer" card - do not break with reviews from authoritative specialists. If one and the same card shows the worthy indicators in this difficult act - it is likely that it is the answer to your question how to choose a motherboard for a computer.

I hope, our article has helped you dedicated to the tricky issue of choosing a motherboard, and you will never become a victim of tricks of sellers or own ignorance. Patience when analyzing the saturated market of motherboards and good luck when buying.

Knowledge obtained from this article on the types of motherboards for PCs will be needed when assembling your computer personally or it will be necessary when you are just going to acquire details for your car. And in general, know all the types of motherboards is useful, and can come true.

In this article, consider the types of motherboards, and our gaze falls only on modern, in demand for the factors that are used today. I will presented very short OverviewAnd then, if necessary, expand to more complete gland parameters.

And here only briefly about the types of format factors of the board.

ATX is a universal fee that will suit almost everyone. She can like both novice users and professionals. This fee can be used on home. desktop machines and on server.

The ATX motherboard form factor assumes the presence of up to 7 slots for connecting devices. Computers working on this gland may be subsequently easily upgraded to more advanced and advanced.

The size of the ATX motherboard allows you to install it in the MINI-Tower and Full-Tower enclosure.

Motherboard Mini ATX

The MINI ATX motherboard has the same functionality as ATX, only a little smaller size. Its form factor assumes up to 6 devices. The compact size of this piece of iron makes it in demand from home users to save space, does not arise a large loss in the characteristics.

Types of MINI ATX motherboards are cheaper than ATX. This makes this type of board budget option.

Motherboard Micro ATX

Micro ATX Form Forms implies its placement in the Mini-Tower package. It is advisable to use this view in the desktop home computers of the middle class.

It is impossible to say, of course, that these are second-rate cars. On the contrary, Micro ATX motherboards are very convenient and economical for home and office use.

Flex ATX Motherboard

Flex ATX is also iron for home and office use. These boards are cheaper than all of the above listed, therefore it is the most budget option.

The Flex ATX motherboard does not imply great performance, so the supernogo computer will not get out of it. For that, it is possible to significantly save on the means.

NLX motherboard

Forms The NLX factor assumes the placement of this board in Mini-Tower. It is a convenience in its use, that is, it is not required to be much effort to install or remove any devices from this board. Most operations can be done even without using scolding. Therefore, it should be recommended to developers and testers.

These types of motherboards and parameters are more suitable for office or home not strained use. Although you can find and powerful advanced options.

Baby-AT (PC and XT);
Full-size AT;
LPX (partially original development);
NLX;
WTX;
VTX, Microbtx, Picobtx.

Modern form factor:

For the first time, the official specification ATX was issued by Intel in July 1995. ATH system boards appeared in the market around the middle of 1996 and quickly took the place of previously used Baby-AT boards. In February 1997, version 2.01 of the Tower ATH specification appeared, after which several more minor changes were made. Intel published a detailed specification of ATX, thereby opening it for third-party manufacturers. Specifications The existing SPE specifications, as well as other types of system boards, can be obtained from Desktop Form Factors (www.formfactors.org). Currently, ATX is the most common form facility of the system boards recommended for most new systems. The ATX Specification will remain expandable for many years; This is similar to the Baby-AT system fee prior.

microatx

The MICROATX motherboard form factor is represented by Intel in December 1997 as an option of a reduced ATX card, intended for small and inexpensive systems. Reducing the form factor of the standard ATX card led to a decrease in the size of the housing, the system board and the power supply and ultimately to reduce the cost of the entire system. In addition, the Microatx form factor is compatible with ATX, which allows the use of the MicroATX system board in a full-size ATX case. But insert a full-sized ATX fee into the Microatx case, as you understand, it is impossible. Currently, mini-tower systems dominate the cheap PC market, despite the fact that their small sizes and narrow corps seriously limit possible upgrades.

reduced width: 244 mm (9.6 inches) instead of 305 mm (12 inches) or 284 mm (11.2 inches);
Reduced number of expansion connectors (four maximum, although in most cases there are only three);
Reduced power supply (SFX / TFX form factor).
The maximum dimensions of the MicroATX system board reach only 9.6 × 9.6 inches (244 × 244 mm) compared with the size of the full-size ATX board (12 × 9.6 inches, or 305 × 244 mm) or MINI-ATX (11.2 × 8.2 inches, or 284 × 208 mm). The size of the system board can be reduced if the location of its mounting holes and connectors will comply with the industrial standard.

In March 1999 intel. Published an addition to the Microatx specification, named FlexATX. This supplement described the system boards of even smaller than Microatx, which allow manufacturers to create small and inexpensive systems. FlexATX boards of reduced size are designed for use in many modern PCs, especially those that differ in low cost, small size and are focused on users working with office applications. In some FlexATX boards, there are even no expansion slots, and only USB or IEEE-1394 / FireWire ports are used instead.