What is the benefit of multiple rails?

[dhgunit]

Is it better stability? I don't know.

I can't really see any reason why I would want 4 12v rails with 18A over a single rail with 60A.

 

[spikoman69]

I think stability? Im not exactly sure, I've always though more rails=better, just because thats what ive always been told.

 

[veg1992]

Is it better stability? I don't know.

I can't really see any reason why I would want 4 12v rails with 18A over a single rail with 60A.

Single rails are generally better, as its more efficient

 

[veedubfreak]

Multiple rail psus are usually cheaper to produce. Thats about the only real "benefit" i can see behind them. When given the choice, go with a quality single rail unit.

 

[wafflehammer]

from all that i've seen single rails are better. multi-rails usual have some power that gets trapped on rails that aren't being used to their full potential...i'm sure it's a small amount you wouldn't notice. I still would rather have a good quality single rail

 

[Jumping_Bean514]

The positives for a multi rail PSU is that if one rail has a catastrophic failure, then its not going to hurt anything on the other rails. This is uncharacteristic of most name brand PSU nowadays though. A single large rail offers more power but with that small risk.

 

[Apokalipse]

Is it better stability? I don't know.

I can't really see any reason why I would want 4 12v rails with 18A over a single rail with 60A.

It means PSU manufacturers can use multiple, cheap power circuits instead of a single, high quality one.
It's more of a marketing gimmick than anything, and often means you have to balance out your components onto each rail.

Basically, I'd get a single rail PSU

 

[SirCyber]

multi-rail
+ more stable
+ more reliable
- not used to full capabilities, thus limiting YOU, the consumer
single-rail
+ full usage of power
+ don't have to balance components
- not protected against rail faults *uncommon*
= go single. more of your power will reach your full potential, possibly also more efficient *beyond efficiency measures*

 

[Apokalipse]

multi-rail
+ more stable
+ more reliable

It's not true that multiple rails make a PSU more stable or reliable.
In fact, if anything, the multiple rail PSU's would probably be less reliable statistically; one of the main reasons for multiple rails is so that manufacturers can use cheap components for each rail that don't have to handle as high load, rather than higher quality components that can.

- not protected against rail faults *uncommon*

what's that supposed to mean?
having multiple rails doesn't provide protection from faults. At best it can isolate some parts that aren't on the faulty rail. But a PSU should protect the PC if a fault occurs by shutting off. And you don't need multiple rails for that.

 

[Nagasama]

i say single rail. my 550vx has 41A of clean, high-stability goodness.