Comparison Asus PRIME B660-PLUS D4 vs Asus PRIME B660M-K D4

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:

— 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.

— 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.

— 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.

— 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).

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.

The number of slots for DDR4 memory sticks provided in the motherboard.

DDR4 is a further (after the third version) development of the DDR standard, released in 2014. Improvements compared to DDR3 are traditional — an increase in operating speed and a decrease in power consumption; The volume of one module can be from 2 to 128 GB. It is this RAM standard that most modern motherboards are designed for; the number of slots for DDR4 is usually 2 or 4, less often — 6 or more.

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.

The maximum amount of RAM that can be installed on the motherboard.

When choosing according to this parameter, it is important to take into account the planned use of the PC and the real needs of the user. So, volumes up to 32 GB inclusive are quite enough to solve any basic problems and run games comfortably, but without a significant reserve for an upgrade. 64 GB is the optimal option for many professional use cases, and for the most resource-intensive tasks like 3D rendering, 96 GB or even 128 GB of memory will not be a limit. The most “capacious” motherboards are compatible with volumes of 192 GB or more - they are mainly top-end solutions for servers and HEDT (see “In the direction”).

You can choose this parameter with a reserve – taking into account a potential RAM upgrade, because installing additional RAM sticks is the simplest way to increase system performance. Taking this factor into account, many relatively simple motherboards support very significant amounts of RAM.

The number of M.2 connectors provided in the design of the motherboard. There are motherboards for 1 M.2 connector, for 2 connectors, for 3 connectors or more.

The M.2 connector is designed to connect advanced internal devices in a miniature form factor — in particular, high-speed SSD drives, as well as expansion cards like Wi-Fi and Bluetooth modules. However, connectors designed to connect only peripherals (Key E) are not included in this number. Nowadays, this is one of the most modern and advanced ways to connect components. But note that different interfaces can be implemented through this connector — SATA or PCI-E, and not necessarily both at once. See "M.2 interface" for details; here we note that SATA has a low speed and is used mainly for low-cost drives, while PCI-E is used for advanced solid-state modules and is also suitable for other types of internal peripherals.

Accordingly, the number of M.2 is the number of components of this format that can be simultaneously connected to the motherboard. At the same time, many modern boards, especially mid-range and top-end ones, are equipped with two or more M.2 connectors, and moreover, with PCI-E support.

Electrical (logical) interfaces implemented through physical M.2 connectors on the motherboard.

See above for more details on such connectors. Here we note that they can work with two types of interfaces:

• SATA is a standard originally created for hard drives. M.2 usually supports the newest version, SATA 3; however, even it is noticeably inferior to PCI-E in terms of speed (600 MB / s) and functionality (only drives);
• PCI-E is the most common modern interface for connecting internal peripherals (otherwise NVMe). Suitable for both expansion cards (such as wireless adapters) and drives, while PCI-E speeds allow you to fully realize the potential of modern SSDs. The maximum communication speed depends on the version of this interface and on the number of lines. In modern M.2 connectors, you can find PCI-E versions 3.0 and 4.0, with speeds of about 1 GB / s and 2 GB / s per lane, respectively; and the number of lanes can be 1, 2 or 4 (PCI-E 1x, 2x and 4x respectively)

Specifically, the M.2 interface in the characteristics of motherboards is indicated by the number of connectors themselves and by the type of interfaces provided for in each of them. For example, the entry "3xSATA / PCI-E 4x" means three connectors that can work both in SATA format and in PCI-E 4x format; and the designation "1xSATA / PCI-E 4x, 1xPCI-E 2x" means two connectors, one of which works as SATA or PCI-E 4x, and the second — only as PCI-E 2x.

The version of the M.2 interface determines both the maximum data transfer rate and the supported devices that can be connected via physical M.2 connectors (see the corresponding paragraph).

The version of the M.2 interface in the specifications of motherboards is usually indicated by the number of connectors themselves and by the PCI-E revision provided for in each of them. For example, the entry “3x4.0” means three connectors capable of supporting PCI-E 4.0; and the designation “2x5.0, 1x4.0” means a trio of connectors, two of which support PCI-E 4.0, and another one supports PCI-E 5.0.

Motherboard-integrated cooling for M.2 SSD drives.

This connector allows you to achieve high speed, however, for the same reason, many M.2 SSDs have high heat dissipation, and additional cooling may be required to avoid overheating. Most often, the simplest radiator in the form of a metal plate is responsible for such cooling — in the case of an SSD, this is quite enough.