What is +12V rail in PSU????

[ZaimGamer]

what is +12V rail???

 

[bgunner]

the PSU is just a power converter. It converts Alternating Current to Direct Current. PC's use Direct current to power them. The +12V rail is a part of the PSU that produces a positive current at 12 volts. This part is called a rail. There are also a 3.3 Volt and a 5 Volt rail also.

 

[ZaimGamer]

for what it is used? i mean there's written 32A for +12V rail,does that mean my psu have 32A for GPU,that's pretty noobish,but i am kinda confused

 

[Sakkura]

Most things in modern PCs use 12V. Only rather small amounts of power are drawn on the other rails. Both the CPU and GPU will draw almost exclusively from the 12V rail. If the power supply has multiple rails, they may draw from different 12V rails, or the GPU can even draw on more than one 12V rail.

 

[Deleted member 217926]

The 12v rail supplies power to the CPU and GPU, the two most power hungry parts of your computer.

 

[bgunner]

The +12V rail is mainly used for GPU and CPU. The 32A means the +12V rail can produce up to 32 amps. Most times the only thing in the system that uses that much amperage is the GPU.

Depending on the GPU you are using depends on how many Amps it will need on the +12V rail. So in short if the GPU you have has a requirement of less than 32 Amps you will be fine, While 32A is low and usually only seen in sub 450W psu's.

 

[ZaimGamer]

ok but what is the case in multiple rails psu like corsair hx 620 have three rails of +12V?

 

[Sakkura]

ok but what is the case in multiple rails psu like corsair hx 620 have three rails of +12V?

Different rails will power different parts of the system. For example, the 4/8-pin CPU power connector, the 24-pin motherboard power connector, and the 6/8-pin graphics card power connectors will not all draw from the same 12V rail, they'll be distributed onto the different rails in a balanced way (so none of the individual rails gets overloaded).

The combined capacity of the 12V rails will not be the sum of what each 12V rail is capable of independently; they have some extra amps available to increase flexibility (so you don't "lose" unused amps on a given rail).

On the Corsair HX620, each 12V rail offers 18A, which is 216W. But the three 12V rails combined can only deliver 600W, not 3 x 216W = 648W.

 

[ZaimGamer]

what about using gpus like r9 290 and r9 290x on multiple rails psu,like hx 620??? it gives 50A combined for all three rails,i think they will be enough

 

[Deleted member 217926]

Don't worry about multiple rails. When a power supply truly has multiple rails ( and it's rare no matter what the marketing department says ) the rails are used as needed. As in power goes where power is needed and you don't have to worry about it. Ever. And despite how that unit is marketed it is a single 12v rail power supply and it doesn't even have over current protection.

Read the last paragraph.

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story2&reid=21

You have what? An old HX 620? 80 Plus rated Seasonic built but based on an old group regulated design. 8 to 10 years ago this was a very high end unit. By today's standards it's average at best. I would begin to wonder how it's held up electrically if I was thinking about throwing a very inefficient and power hungry AMD card at it. As in I might replace it just to be sure if it's been in use for all those years.