12V rail question

[Duke{CLR}]

Someone mentioned earlier that there was an advantage to a single 12V rail and I have noticed that PSUs with a single rail are a bit more expensive. So what are the advantages to a single 12V rail?

[DougBob]

Someone mentioned earlier that there was an advantage to a single 12V rail and I have noticed that PSUs with a single rail are a bit more expensive. So what are the advantages to a single 12V rail?

To tell you the truth I've never paid any attention to it.

[Donziboy2]

Well the reasoning for using more then 1 rail is to separate items that require large amounts of power from other items that pull a certain amount all the time. IE put your mobo/floppy/cdrom/hdd/fans on 1 rail and your video cards on another rail. So that when your video card goes from pulling 50 watts to 300 watts it doesnt cause a spike in power and cause system instability or crashes. Also in splitting the rails you can use smaller components, psu's have a form factor so cramming a single rail part for a 1200 watt psu may not be as easy as 2 600 watt rails.

And you would think more rails would mean higher cost since you need more voltage sensors to track the extra rails but apparently not. I prefer more then 1 encase a rail dies it doesn't fry my entire system only part of it.

[Furryappleseed]

Well from what I have seen, it makes sure that power doesn't get "trapped" on one rail. My psu has 3 rails and the 3rd is dedicated completely to the 2 pci-e power connectors I have. I guess in certain configurations you could overload one rail while others are barely being pushed. With a single rail you never need to worry about if components are on the right rail and such.

Pc power and cooling has been doing the single rail thing for as long as I can remember. Only in recent year or so have I seen others doing it. I don't know if higher quality components are needed for the single rail systems but thats what i'm guessing since their price tends to be a little more expensive

[juneau]

It's all marketting tbh. PSU's started with single rails when nobody paid any attention to them. Then it came to having 3 or more rails, because more is better right? Then we went back to one because one big strong manly rail is better than 3 or 4 weakling rails. Blah blah blah lol.

As long as the PSU has good quality components and is stable with the amps and watts it produces you could have 1 rails or 4 rails. Makes no difference.

[DougBob]

I would have to see the schematics. They probably all come thru the same transformer and the same rectifier and voltage divider circuits.

[{CLR} Cobalt]

Yeah... what DougBob said.

[Furryappleseed]

So what's all this rubbish about multiple 12 volt rails?

Looks like a good read.