Computer technology is evolving. The shape of the devices, their dimensions and specifications are changing. Today we will consider such a concept as the form factor, and its ATX variant is the most popular and demanded.
Form factor
To go to the topic of the article, you need to understand the basic concept. The form factor is the standardization of IT equipment. Using it, you can determine the size of the device, the main technical indicators, the availability of additional parts, their location.
Now, speaking of the form factor, people remember the motherboard. Earlier, the term was applied to phone cases, communication equipment, and other PC components.
Given that the form factor is a standardized concept, it is referred to as recommended parameters. That is, thanks to the index, which indicate a specific form factor, it is possible to indicate the required and additional parameters. Developers are trying to take the standard for granted and be guided by it when creating the appropriate component.
Variety
The ATX form factor is not the only standard for accessories. But it was this option that became popular for mass production of PCs. The world saw him for the first time in 1995, and Intel became the manufacturer of this architecture. XT, AT, and Baby-AT standards already existed, which IBM introduced in 1983.
The ATX form factor has influenced the emergence of modified standards. Shortened formats began to appear, with fewer slots and compact sizes. By 2005, a mobile standard was developed that was optimized for processors.
Office computers also began to be equipped with various components of certain standards. Boards began to appear, which were used in complex industries. Such modifications to the standard have been known since 2004. The ATX form factor has transformed into SSI CEB, DTX, BTX, etc.
ATX
This form factor became popular back in 1995, but has gained the most distribution since 2001. The standard has become dominant in PC manufacturing. It affects not only the size of the board or other component. ATX dictates the standard PSU, PC case, the placement of slots and connectors, the shape and location of the slots, mount and PSU parameters.
Intel has been pondering over what the continuation of the AT form factor should be. By 1995, developers introduced the new ATX standard. In addition to this company, other manufacturers who supplied OEM equipment thought about changing the outdated standard. After the new standard was picked up by those who supplied the motherboard and PSU.
Over the entire period of its existence, 12 specifications have been released. ATX form factor dimensions are standard: in millimeters - 305 x 244, in inches - 12 x 9.6. Modifications that were issued under other names were developed on the basis of ATX, but had differences in port layout, overall dimensions, etc.
So, in 2003, Intel wanted to introduce BTX. This new standard more effectively cools the PC system unit. The developers wanted to slowly remove from the markets the ATX, which maintained high heat inside the system unit. But even such a danger as overheating of the entire system did not contribute to successfully changing the format to BTX.
Most manufacturers refused to distribute it, since a decrease in power dissipation showed positive results, and in the future it was still possible to achieve good results when cooling the case and without changing the standard. As a result, by 2011, it became clear that it was not necessary to replace the ATX form factor.
Major changes
Such a successful invention in this area was not worth the wait. The user received major changes regarding the previous version of AT. The processor motherboard began to deal with power. Standby power is supplied to it even when it is turned off. The motherboard provides the functioning of the control unit and some peripheral devices.
It became possible to replace the fan with a larger one and place it at the bottom of the PSU. The air flow became more powerful and covered more elements in the system unit. The number of revolutions, and accordingly the noise, changed. Over time, there was a tendency to place the power supply at the bottom of the case.
Food
The change in form factor brought a change in the format of the power connector. This was caused by the fact that in the previous format, two similar connectors were connected to unsupported slots, which caused a system crash. In the process of increasing power consumption, it was necessary to increase the number of power contacts. Developers started with 20, later there were more of them, and additional connectors appeared.
Interface panel
The interface panel has become freer. Previously, there was a keyboard slot, and expansion boards were installed in special holes. The ATX form factor added space for a communicator to the keyboard slot. The free space was occupied by a rectangular “slot” of standardized size, where developers placed the necessary slots.
Starting power supply
In addition to the fact that there is a motherboard ATX form factor, you can find PSU of this standard. Since the development of the format lasted nine years, during this time the developers tried not only to change the connector, but also to make it compatible with previous forms.
So, originally used a connector with 20 power contacts. This option was popular before the appearance of the motherboard with the PCI-Express bus. Then came the connector with 24 pins. In order for this option to be supported by previous versions, the “bonus” 4 contacts could be removed, and the board would work with twenty.
Processor changes
When the new Pentium 4 and Athlon 64 processors began to appear, I had to rework the standard to version 2.0. So, motherboards began to require 12 V for the main bus. The power supply, the ATX form factor of which was also updated to the second version, should have received an additional connector. So there was an additional connector for another 4 pins.
After that, options with complex contacts began to appear. For example, the 24 + 4 + 6-pin connector became popular for motherboards that received several PCI-E 16x ports. A 24 + 4 + 4-pin actually had an additional 8-pin connector, which consisted of two slots of 4 contacts. Thus, it began to be used for motherboards that had high power consumption.
This decision with the combination of two 4-pin connectors was caused in order not to deprive the user of connecting the model to older motherboards. So, one connector was detached from the other, and we got a 24 + 4-pin wire.
Body
In addition to the motherboard and PSU, the case has a certain standardization. The ATX form factor in this case is the most modern and is suitable for motherboards of the same format. Such a case involves easier access to the entire inner periphery. It has excellent ventilation inside. Allows you to install more than one full-size board.
Despite the same name, in the ATX case you can put the motherboard format micro-ATX. We will talk briefly about this standard later.
Compact version
The micro-ATX form factor appeared a little later than the main standard - in 1997. The motherboard of this format has 244 x 244 mm. The option was developed for processors with an outdated x86 architecture.
In the process of creation, it was decided to maintain electrical and mechanical compatibility with the previous standard. As a result, the main difference remains the dimensions of the boards, the number of slots and integrated peripherals. Micro-ATX is launched on the market with an integrated graphics card, thereby indicating the intended purpose of this standard. PCs with this form factor are suitable for office work and are not designed for gaming projects, since the integrated video card is mediocre.
Other options
In addition to ATX and micro-ATX, there was a mini-ATX form factor that is nowhere to be found anywhere else. Its dimensions are 284 x 208 mm. FlexATX also appeared, which had dimensions of 244 x 190 mm. This modification is flexible and allows the manufacturer to independently solve many problems.
So, he can choose the size and location of the PSU. Participate in changes regarding new processor technologies. But this option could not "fight" with ATX and remains in the background.