What are the power specifications for desktop computers?

At, ATX, SFX, TFX, FLEX ... I believe many netizens jumped up and shouted, "What the hell is this?" Ancestral code? No, it's not. Today, the power supply you do not know the second phase of the story, is about these power supply code. What is that? power supply is that rigid square, complex circuit and the ordinary people do not understand the composition of electronic components, but also divided into so many specifications? Yes, because everyone is brainwashed by the standardized Intel ATX specs, causing us to have no knowledge of the specifications of the power supply itself. Today, taking advantage of this issue of power lectures, we return to the power specification itself and talk about standards.

We introduce the power specifications that appear in the chronological order in which the specifications appear, because the ATX is the current mainstream power supply specifications, the space of the flower is more natural. In fact, the standard is very simple to distinguish between different specifications of the power supply, that is the shape .

　　At

Since the 286 era, at Power has been the Standard PC configuration, this situation until the 586 era is over. Power in power than the ATX power supply is smaller, the boot need to go through the front panel switch.

The at power supply is similar in size to the current ATX power supply, but the main power connector is different from the ATX power supply. The at power supply has 2 motherboard power connectors (P8 and P9), each with 6 pins connecting the power system to the motherboard. It is worth mentioning that the design of the P8 and P9 was not completely standardized, only because IBM originally used this design, so it was promoted.

Unique P8/P9 Connectors

All at power supplies using the P8/P9 connector ensure that the black wire (ground) of the power cable is put together during installation. In addition, there is usually a card ring to prevent them from connecting to the motherboard pins, so it is most important that they are connected in the correct order without omitting any pins, otherwise the motherboard and all parts plugged in above are subject to catastrophic damage when the power supply is powered up.

Because the power is small, the use is inconvenient, the at power supply has already belonged to the elimination power type, at present it is very difficult to see the PC system using at power supply.

　　Atx

ATX Power Supply

ATX Power Supply is currently the most popular power specifications, the first in 1995 by Intel Corporation, the current version of the latest specification is ATX12V 2.31 version.

The ATX power supply was a major improvement on the main power connector at the time, which increased the 3.3V and +5VSB output voltages and a ps-on signal. Using +5VSB and ps-on signals, we can realize the functions of software shutdown, keyboard startup, remote wake-up and so on.

Familiar ATX Power Wire standard

Prior to the ATX12V 2.0 version, the 20-pin style connector was first used in the ATX-shaped power supply system, and in order to meet the requirements of high-power CPUs, the ATX 12V 4PIN +12v voltage to the CPU was increased to +12.8v (+/-12%), reducing main The +12v current strength of connect, in simple terms, becomes a 20pin+4pin configuration.

From the increase in output capacity to increase the cooling settings, and then to support the latest accessories interface standards, ATX12V constantly develop. is currently ATX12V 2.3 version, will +12v1 output capacity and +12v2 output capacity, while requiring power to have 80% or more conversion efficiency, and power factor is required to be 0.9, in line with the requirements of energy saving and environmental protection.

　　SFX

SFX Power, smaller than ATX

Intel introduced a smaller MICRO-ATX motherboard profile in December 1997, as well as a smaller SFX (Small form Factor, small profile) power supply. Since then, SFX Power has been widely used in many new small PCs. Currently, the latest version of the SFX specification is the SFX12V 3.0 edition.

The SFX power supply is specially designed for small systems that include a limited number of hardware. It provides slightly smaller continuous power and 4-voltage (+5v, +12v, -12v and +3.3v). For small systems, the power of this capacity is sufficient. SFX power supply generally does not provide -5v voltage, but for the current motherboard has little impact, after all -5v and practical -5v of the ISA slot has been eliminated.

SFX The main power connector is the same as ATX, after all, the two are compatible, so players do not have to worry about the motherboard incompatibility after selecting the SFX power supply. However, due to the low number of SFX power supply, high integration, the price is more expensive than the ATX power supply.