Big problems running X1900 in CrossFire

[OC_newbie]

Well, I'm only using the monster 1320W PSU for DI/LN2 overclocking. For regular testing I have here Tagan 480W, Silverstone 560W (one 12V rail), Silverstone 600W (four 12V rails), Antec 550W and few others. In my tests Silverstone 600W didn't handle FX-60 + Radeon X1900 CrossFire @ stock speeds.. I had to change to Silverstone 560W which has only one 12V rail.

I noticed that @ default clocks ATI Radeon X1900 XTX draws 24,5 A according to ATITool.

SO this OCZ 600w PSU can't run my system? It only has 20A on but 12v rails so thats to low I guess, cuz running just one X1900 XTX work perfect, only when I enable crossfire I get major problems. Thanks for all the help everyone, I learned alot now. So now I should shop for a PSU with 600W or higher with one big 12v rail with 50A?

[Sampsa]

SO this OCZ 600w PSU can't run my system? It only has 20A on but 12v rails so thats to low I guess, cuz running just one X1900 XTX work perfect, only when I enable crossfire I get major problems. Thanks for all the help everyone, I learned alot now. So now I should shop for a PSU with 600W or higher with one big 12v rail with 50A?

I'm pretty sure it's the PSU which is causing you problems with CrossFire.

PS. Single Radeon X1800 XT shows 38,2 A GPU current draw regarding ATITool... I'm not so sure if this value is the true

[JuanFlaiter]

I had problems in 2x X1900 with the Antec TrueControl 2.0, CoolerMaster 600w and OCZ 600w. No problems with only one 12v line PSU, even with PSU that had less amperage (A TP I).

This was the answer my ATI representant forwarded me from ATI Support....

#1 The short answer is that there is a list of CrossFire certified power
supplies on ati.com, and the ones the reviewer was having issues with are
not on that list, so we can't guarantee that they will work. That said, I'm
still trying to find out the reasons why they aren't on the list.

Why not admit CF has issues with most dual rail PSUs?

[Dumo]

I'm pretty sure it's the PSU which is causing you problems with CrossFire.

PS. Single Radeon X1800 XT shows 38,2 A GPU current draw regarding ATITool... I'm not so sure if this value is the true

My Enermax 660W with multiple 12V just went kaput with FX60 and single 1900XTX overclocked

[Wam7]

Some interesting info I recieved from a FSP tech guy in relation to the Epsilon 600w.

If you are planning to upgrade to X1900XT CrossFire, I think you made the right choice for having Epsilon then.

An extra piece of info for your reference, I was talking to our PM in Taiwan these 2 days regarding the max amp for 12V on Epsilon. It shows max 15A at the moment but they have updated and passed the safety certificates on 18A already. The OCP is actually 20A.

Hmm, that's probably why this PSU seems to succeed where other notable ones apparently fail.

[mrtell]

I can confirm this, talking to FSP I got this reply,
FSP Epsilon

"What I mentioned applies to the present Epsilon 600/ 700.

Yes, the present ones have been reclassified. Even though it says 15A, it's actually 18A (with Over Current Protection of 20A).

Grace
__________________
FSP Group - www.FSPgroup.co.uk "