Possible PSU issue?

[playworker]

Hello,

I've just built a new gaming PC, all working beautifully apart from one issue:

I went for a X1900 XT Crossfire setup thanks to the special offers on here this week Installed the Catalyst 6.3 drivers and the 0311 BIOS for the A8R32-MVP, but I have problems with the PC shutting down when Crossfire is enabled and I try playing games. Managed to play HL2 for a few minutes but the PC just shutdown when loading the next section, WoW doesn't get past the initial menu screen. Everything works 100% when I disable Crossfire and just use the one GPU - I'm thinking this is probably a PSU problem as I've only got a 550W one at the moment, placed an order for a 650W anyway but I just wanted second opinions - is there anything else that could cause this that I might have overlooked?

Cheers

 

[playworker]

Yeah man - game pauses for a second then complete power-off. Have to remove and replace the power cable from the PSU before it'll power back up again - scared the crap outta me when it first happened Thought I'd blown something in a really bad way

My guess is it's trying to draw too much power from the PSU so the PSU shuts down for safety reasons?

 

[playworker]

Aha! That makes more sense