What are PSU rails?

Toggle sidebar Toggle sidebar
T

Thegame741

Reputable
Sep 11, 2014
53
0
4,630
+12v, 12v etc. What do these do or stand for? Would i need to pay attention to the rail thing while making the actual build? Should i even know anything about rails while doing my build or is it not that necessary? Your help is appreciated. Thank you very much
 
Solution
Vexillarius
Different PC parts need different voltages. A wall socket only gives one specific voltage, depending on where you live 120v, 130v, 230v or 240v. All of those are way too high for PC component, so the PSU converts the power to lower voltage DC power. Some components need 5v, some need 12v, etc so a PSU has a 12v rail, a 5v rail, a 3.3v rail, etc to deliver the right voltage to the right cables.

The actual amount of power that the PSU can deliver is determined by the maximum amperage on each rail. High amps on the 12v rail is by far the most important, followed by the 5v and 3.3v rails.

Some PSUs have more than one 12v rail, because it can be easier/cheaper to implement multiple lower amp rails than one high amp rail. Single rail used...
Sort by date Sort by votes
Vexillarius

Vexillarius

Reputable
Aug 23, 2014
1,434
0
5,960
Different PC parts need different voltages. A wall socket only gives one specific voltage, depending on where you live 120v, 130v, 230v or 240v. All of those are way too high for PC component, so the PSU converts the power to lower voltage DC power. Some components need 5v, some need 12v, etc so a PSU has a 12v rail, a 5v rail, a 3.3v rail, etc to deliver the right voltage to the right cables.

The actual amount of power that the PSU can deliver is determined by the maximum amperage on each rail. High amps on the 12v rail is by far the most important, followed by the 5v and 3.3v rails.

Some PSUs have more than one 12v rail, because it can be easier/cheaper to implement multiple lower amp rails than one high amp rail. Single rail used to be better, but a quality PSU with multiple 12v rails will perform just as well as a single 12v rail unit these days. No need to worry about it.
 
Upvote 0 Downvote
Solution
S

Saberus

Distinguished
Aug 23, 2013
1,661
5
20,465
Rails are individual, independent power feeds.

They were initially set up to avoid overloading wires. In a true multi-rail PSU, they are usually 20 amps per rail, and you can't split power for a part over two. This can lead to problems where the PSU could crank out 2 20 amp rails, and after two GPUs eat up 16 amps each, the CPU needing 6 amps can't run, because neither rail could handle the load on its own.

It is something to look out for, but some PSU tie the rails together anyway.
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom