Split 12v rails or not ?

[Tuvoc]

I'm looking at this PSU at the moment
BeQuiet Pure Power L8 530W '80 Plus Bronze' Modular Power Supply [BN181]
http://www.overclockers.co.uk/showproduct.php?prodid=CA-053-BQ

What bothers me are the two 12v rails. I've always believed in a single large rail, so the power can go where it is needed. What if one 12V rail reaches capacity ? The other just sits there wasted ?

I'm not a gamer, so the PSU just has to feed an overclocked Phenom II X6, and 3 hard drives, and the motherboard etc of course. I take it in that scenario all the power comes from one rail and indeed the other sits idle ?

 

[Tealc]

PSUs tend to have the rails split so just plugging stuff in logically splits the load properly. It isn't that long since split rails were a necessary part of the ATX standard.

PSUs also tend to have one rail electronically split into multiples using current limiting devices rather than independent transformers and regulators so no inbalance can occur really.

 

[Admiral Huddy]

Technically, all 12v rails are connected to the same 12v source but are independent in terms of the cabling thus avoiding any potential overheating and damage. You are correct in saying that multiple rails do have a ceiling and potentially could be exceed but I have to say I've never had any issues with this. Nvidia insist that each PCI-e has it's own rail.. Hence PSUs with SLI or Crossfire certification but it doesn't make a real difference.

The PSU you have selected has +12v1 (a) 28 and +12v2 (a) 20 which should be more than enough to accommodate your system without worrying about under or over usage.

As long as the PSU meets all your system power requirements and is an efficient, branded and trusted PSU you should have too many problems..

 

[TheNameIsJambo]

Splitting the rails is only done for safety IMHO.

Less amperes = Less heat.

Less amperes = Lower chance of death; from fires or electrocution.

Single rails have been around for a long, long time, and there's nothing wrong with them.