How to set up Dual Power Supplies

[DaPoets]

Say in theory I wanted to use a 2nd power supply just to power 1 PCIe video card, how would I go about doing it?
I have an antec trio 650w and Antec said that it's not powerful enough to run my crossfire setup (2 x1950pro's pcie 512meg) and I should go w/ the 850... but I want to make sure that this is actually the problem since ATI says that my 650 is actually certified for crossfire... The Antec guy on the phone said stuff about amps per rail or something and that my 650 may not be supplying enough for crossfire but is supplying enough for the cards to run w/ out crossfire enabled.

[SeasonalEclipse]

http://www.ocforums.com/showthread.php?t=88976
That may aid you.

[DaPoets]

Thanks...

I now realize that it's the 12v not giving enough amps.... so adding a 2nd psu won't fix my issue... Crossfire for my cards require 38amps on the 12v rail and my "crossfire certified" PSU from Antec only does 19amps on 12v rails...

[JamesXP]

You could probably just link the second PSU up and run one card off that PSU.

[DaPoets]

But I think my issue is amps per rail, not total wattage... Or am I looking at this wrong...

[SeasonalEclipse]

Id say instead of running 2 decent PSUs to get 1 kick tush one.

[JamesXP]

Kick Tush hehe,


HX520 = One 40A Rail
HX620 = One 50A Rail

:)

[DaPoets]

yeah I know I know, but I wanted to test before I spent money.

I'm looking for a PSU now that will supply my needs of over 38a per 12v rail for an ATX case containing 2HD, 1DVDrom, 1CDrom, quad core OC 3.2ghz, 4gigs ram, 8 fans and have room for future power sucking devices...

for the cheapest price of course...

[SeasonalEclipse]

http://www.newegg.com/Product/Product.aspx?Item=N82E16817341003 That should do!! (kidding! I know its over kill)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817341002
That one is a great deal and should run everything you throw at it.

[Evilsizer]

well lets do a bit of math real quick... you want a psu with 38amps per rail... never seen one... all mulit rail units have a max of 18per rail. now you can find high amp single rail units. 38amp x 12v = 456watts, now you want a dual or even triple rail with that amount... thats just nuts... the dude at antec lied to you.

lets just say for instance you have 2 psus the same wattage and model. you could do this one of 2 ways. my LL-A10B case came with a pass thru cable so that when i power up my system the second psu would turn on. you could find such a cable for about $5 bucks. what i did one time was hot wire the second psu on since it was just power a 6800U at the time while i figured out the cause of the video issue(yea it was a bad card,so it was off for RMA).

if you havent seen this list, i would suggest you look over it. alot of psu's under $150 with sli/cf support
http://www.jonnyguru.net/forums/showthread.php?t=1460