Power phases
The number of processor power phases provided on the motherboard.
Very simplistically, phases can be described as electronic blocks of a special design, through which power is supplied to the processor. The task of such blocks is to optimize this power, in particular, to minimize power surges when the load on the processor changes. In general, the more phases, the lower the load on each of them, the more stable the power supply and the more durable the electronics of the board. And the more powerful the CPU and the more cores it has, the more phases it needs; this number increases even more if the processor is planned to be overclocked. For example, for a conventional quad-core chip, only four phases are often enough, and for an overclocked one, at least eight may be needed. It is because of this that powerful processors can have problems when used on inexpensive low-phase motherboards.
Detailed recommendations on choosing the number of phases for specific CPU series and models can be found in special sources (including the documentation for CPU itself). Here we note that with numerous phases on the motherboard (more than 8), some of them can be virtual. To do this, real electronic blocks are supplemented with doublers or even triplers, which, formally, increases the number of phases: for example, 12 claimed phases can represent 6 physical blocks with doublers. However, virtual phases are much inferior to real ones in terms of capabilities — in fact, t...hey are just additions that slightly improve the characteristics of real phases. So, let's say, in our example, it is more correct to speak not about twelve, but only about six (though improved) phases. These nuances must be specified when choosing a motherboard.
M.2 version
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.
M.2 SSD cooling
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.
Thunderbolt AIC connector
5-pin connector that allows you to connect an expansion card. It, in turn, provides high-speed data exchange (up to 40 Gbps), the ability to connect external monitors, high-speed charging of compatible devices, etc.
BIOS FlashBack
Motherboards that support
BIOS FlashBack provide the ability to flash or restore the BIOS without a processor, video card or memory. The main purpose of the function is to provide users with the ability to update the BIOS in cases where the current version is incompatible with the installed processor or other computer components, which may lead to the inability to start the system. As a rule, the motherboard provides for this a USB connector for a flash drive and a special button (usually labeled BIOS Flashback) - pressing it initiates the update process.
On a separate line, we note that the BIOS FlashBack function can be called differently depending on the manufacturer: in motherboards from ASRock and Asus - BIOS FlashBack, from Gigabyte - Q-Flash Plus, from MSI - Flash BIOS, etc.
CPU Fan 4-pin
A four-pin connector used to connect a processor cooling fan. The first contact in it corresponds to the black wire of the cooler — it is the "ground" or minus of the power supply. The second contact is the plus of the power supply (yellow or red cooler wire). The third one is involved in measuring the rotation speed of the impeller (green or yellow fan wire). The fourth pin, corresponding to the blue wire, receives control signals from the PWM controller to adjust the cooler rotation speed depending on the temperature of the processor.
CPU/Water Pump Fan 4-pin
A four-pin connector for connecting a water cooling pump fan. It can also be used to turn on an additional CPU cooler.