Powerful enough PSU?

[Mazurizi]

Hello, Tom's Hardware Dudes!

Need a little help / advice on my newest gaming rig. I have built it myself with these specs:

i7 930 @ 4GHz
6GB DDR3 Patriot RAM
Gigabyte GA-EX58-UD3R
2 x ATI Radeon 5870 XXX Edition
Corsair 850W Modular PSU
2 x HDDs (250GB and 1TB)
A DVD Drive
6 x 120mm Case Fans

Windows 7 - 64 Bit
Latest ATI Drivers 10.5

I'm having alot of problems getting the graphics cards to perform correctly - at first they were artifacting, so I tested each card individually and they worked fine. But they don't want to work together - I have tried the basics:
-CrossFire Bridge is on
-Tried Dual Crossfire Bridges

The cards are really close together - and do get rather hot, peaking at roughly 78C which isn't bad at all. I managed to get them to boot in Crossfire, but it was artifacting on the Desktop - I managed to change the Memory and Core Clocks down to Minimum and ran Furmark for well over an hour without any problems - again peaking at 78C.

So what do you guys think the issue may be? A bigger PSU? If so, any recommendations?

 

[Chuckles_]

Did you have that OC established prior to adding the second card?

 

[Mazurizi]

Yes, the CPU Overclock has been stable and the temps are good on it.

 

[Chuckles_]

Did you experience these issues prior to the OC?

 

[Mazurizi]

The OC was in place before I put the graphics cards in the system - I bought it OCed to 4GHz.

I'll set the clocks back to defaults and try it again with the cards again tomorrow. Been fiddling with it for the last four hours now and I'm bored of it - so I'll try it tomorrow.

Currently runnning on 1 ATI Radeon 5870

 

[Chuckles_]

Ahh OK... I'd bet that's your problem.