280gtx SLI/Single Won't Boot.

[stryc]

I have tried two different brands of 280GTX, EVGA and now MSI. My system will not boot with in a single 280GTX GPU or SLI. If I install one of my 8800 cards in the vacant PCIE slot with or without the two 280GTX installed, she boots right up! Once my system is warmed up, I can shut down, remove the 8800 card and boot up and game fine on my 2 280GTXs. Sure could use some help with this one. I'm thinking I might be able to increase a voltage setting in my bios to spool up my power supply but I don't know where to start. Any ideas?

System:

ASUS STRIKER EXTREME (First generation nForce 680i SLI chipset , not the Extreme II)
Intel Core DUO 6850
Corsair DDR2
COOLMAX cuq-1200b 1200w PSU
Blah blah blah ....
.....

 

[jerreece]

Normally I'd suggest making sure your PSU is good enough (I'd hope 1200W has enough amperage, so I can't imagine that's your problem.) Then I'd suggest making sure your PCI-E power connectors are plugged in, etc.

But assuming those are correct, your problem doesn't make sense. LOL! Not sure what the problem would be, unless of course your motherboard for some reason doesn't want to work with the new GTX cards. BIOS Update available?

EDIT: As a side note, I'm wondering if your Core Duo 6850 creates a bottle neck for an SLI setup with GTX 280's.

 

[stryc]

I've updated the bios. Power supply is good. I can have both 280GTXs installed and my system won't boot untill I install my old 8800 in the remaining PCIE slot.