Advantage & Disadvantage of Single 12v Rail Power Supply

[robin45]

Hi,

I was wondering if someone can tell me about the advantage & disadvantage of single 12v rail power supply vs multiple 12v rails. The reason for asking is, I am currently having a BFG 800 watt psu with 4, +12v rails each rated at 20 amps. Will I get better results from my cards if i switched to an 800 watt or better single. This seems like an easy question to me but I cant seem to find the answer anywhere.

[Tomaz]

It's actually cheaper to make a single +12V rail PSU bec all of the components used in splitting up and limiting each rail. Most "multiple rail" PSUs connect to a single rail within the PSU anyway. So you just need to make sure to get your PSU from a quality manufacturer. In the case of a multi rail, as long as the unit has rails rated 18-20A then you should have no issues powering up and running the PC.

[Theodot]

Advantage of Single 12v Rail Power Supply is that, the rails themselves are capable of far more power output than any PCIe graphics card would ever need. A builder needs to be aware when it is crossing the line between a mid range and a high powered system. In essence the wire becomes a heating element and a short like that could end very bad.

[Barclay]

Any good quality, well made supply today with adequate power for its respective use. Since there are no "limits" on single +12V rail PSU's, you can not overload the rails and cause them to shut down because I have heard lots of good things about PC Power and Cooling PSU's and from what i see they only use single rail setups. Single rail designs actually have some bad qualities.