Form factor
The form factor of the motherboard determines, first of all, its physical dimensions, and, accordingly, a number of parameters directly related to them: type of computer case, installation method, type of power connector, number of slots for additional boards (expansion slots), etc. At the moment, there are such main form factors of motherboards:
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ATX. One of the most common form factors for PC motherboards. The standard size of such a board is 30.5x24.4 cm, it has up to 7 expansion slots and a 24-pin or (less often, in older models) 20-pin power connector.
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Micro-ATX. A slightly reduced version of the ATX form factor, with more compact dimensions (usually 24.4x24.4 cm) and, accordingly, fewer places for peripherals — there are usually only two slots for "RAM", expansion slots — from two to four. Nevertheless, despite the limited size, such boards can be intended for quite powerful systems.
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Mini-ITX. Motherboards of compact dimensions (17x17 cm). Designed for use primarily in small form factor computers (small form factor, SFF), in other words, compact PCs. According to the mounting specifications and the location of connectors and slots, they are compatible with ATX standard cases. They usually have one expansion slot.
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mini-STX. Another representative of compact form factors, assuming a boar
...d size of 140x147 mm. Thus, the overall size is almost a third smaller than mini-ITX. At the same time, such motherboards often have seats for fairly powerful processors (for example, the LGA 1151 socket for Intel Core chips) and are made based on the corresponding TDP values. But expansion slots, usually, are absent.
— micro DTX. A relatively new compact form factor, which is not common, mainly among rather specific motherboards — in particular, models designed for cases in the PIO form factor. This form factor is characterized by a very small size and weight and allows you to mount the case directly behind the monitor, on a standard VESA mount. One of the features of "motherboards" for such systems is that the graphics card is installed along the board, and not perpendicularly — accordingly, the PCI-E 16x connector (see below) has a non-standard location. At the same time, micro-DTX boards are similar in terms of fasteners to microATX and can be used in cases of the corresponding form factor (except that additional equipment may be required for the correct installation of a graphics card). The standard size of such a board is 170 x 170 mm, similar to mini-ITX.
— mini DTX. An intermediate format between the microDTX described above and the original DTX; sometimes also described as an extended mini-ITX version. It has a standard size of 170 x 203 mm and can be equipped with two expansion slots (mini-ITX and mini-DTX have one such slot); it is completely similar in application — it is intended mainly for compact cases, in particular, HTPC computers.
— XL-ATX. Larger version of the ATX form factor. While not yet a common standard, size options include 32.5x24.4cm with 8 expansion slots and 34.3x26.2cm with up to 9 expansion slots.
— Thin mini-ITX. A “thin” version of the reduced mini-ITX form factor described above: according to the official specification, the total thickness of the thin mini-ITX board should not exceed 25 mm. Also designed for the most miniature computers — in particular, HTPC.
— E-ATX. The letter E in the name of this form factor stands for "Extended" — extended. True to its name, E-ATX is another enlarged version of ATX using 30.5x33cm boards.
— EEB. Full name SSI EEB. The form factor used in server systems (see “By direction”) provides a board size of 30.5x33 cm.
— CEB. The full name is SSI CEB. Another form factor of "server" motherboards. In fact, it is a narrower version of the EEB described above, with a width reduced to 25.9 cm (with the same height of 30.5 cm).
— flex-ATX. One of the compact variations of ATX, which provides board dimensions of less than 229x191 mm, as well as less than 3 expansion slots. At the same time, in terms of the location of the mounting holes, this standard is identical to microATX; in fact, it was developed as a potential replacement for the latter, but for a number of reasons it did not receive much distribution, although it continues to be produced.
— Non-standard (Custom). The name Proprietary is also used. Motherboards that do not conform to standard form factors and are designed for cases of special sizes (usually branded ones).Size (HxW)
Motherboard dimensions in height and width. It is assumed that the traditional placement of motherboards is vertical, so in this case one of the dimensions is called not the length, but the height.
Motherboard sizes are largely determined by their form factors (see above), however, the size of a particular motherboard may differ slightly from the standard adopted for this form factor. In addition, it is usually easier to clarify the dimensions according to the characteristics of a particular motherboard than to look for or remember general information on the form factor. Therefore, size data can be given even for models that fully comply with the standard.
The third dimension — thickness — is considered less important for a number of reasons, so it is often omitted.
Max. clock frequency
The maximum RAM clock speed supported by the motherboard. The actual clock frequency of the installed RAM modules should not exceed this indicator — otherwise, malfunctions are possible, and the capabilities of the “RAM” cannot be used to the fullest.
For modern PCs, a RAM frequency of
1500 – 2000 MHz or
less is considered very low,
2000 – 2500 MHz is modest,
2500 – 3000 MHz is average,
3000 – 3500 MHz is above average, and the most advanced boards can support frequencies of
3500 – 4000 MHz and even
more than 4000 MHz.
AMP
The ability of the motherboard to work with RAM modules that support AMP technology (AMD Memory Profiles). This technology was developed by AMD; it is used in motherboards and RAM blocks and only works if both of these system components are AMP compatible. A similar technology from Intel is called XMP.
The main function of AMP is to facilitate system overclocking (“overclocking”): special overclocking profiles are “sewn” into memory with this technology, and if desired, the user can only select one of these profiles without resorting to complex configuration procedures. This is not only easier, but also safer: every profile added to the bar is tested for stability.
XMP
The ability of the motherboard to work with RAM modules that support
XMP (Extreme Memory Profiles) technology. This technology was developed by Intel; it is used in motherboards and RAM blocks and only works if both of these system components are XMP compliant. A similar technology from AMD is called AMP.
The main function of XMP is to facilitate system overclocking (“overclocking”): special overclocking profiles are “sewn” into the memory with this technology, and if desired, the user can only select one of these profiles without resorting to complex configuration procedures. This is not only easier, but also safer: every profile added to the bar is tested for stability.
PCI slots
The number of PCI slots provided in the design of the motherboard.
These slots are used for expansion cards. At the same time, technically, this interface is considered obsolete — in particular, it is noticeably inferior to the newer PCI-E in terms of data transfer speed (up to 533 MB / s). Nevertheless, for some types of components (for example, sound cards), such features are quite enough; and the use of PCI allows you to leave free PCI-E slots that may be needed for more demanding peripherals. So even nowadays, both motherboards with PCI slots and components with such a connection can still be found on the market.
Fan power connectors
The number of connectors for powering coolers and fans provided in the motherboard. A processor cooler is usually connected to such a connector, and fans of other system components — video cards, cases, etc. can also be powered from the "motherboard"; sometimes it is more convenient than pulling power directly from the PSU (at least you can reduce the number of wires in the case). Many modern boards are equipped with
4 or more connectors of this type.