EP45-UD3P + GTX275 + GTX260 NON SLI for Folding?

[ToBXaH]

Specs:
E8400 3.0GHz
Gigabyte EP45-UD3P Rev 1.0 (F9) bios
4GB G SKILL DDR2
BFG GTX 275 x16 (190.38 Driver)
PNY GTX 260 x8 (190.38 Driver)
WD 300GB 10k RPM
WD 500GB 7.5k RPM
Creative SB Fata1ty Pro
700Watt PSU

I realize the EP45-UD3P is a crossfire ready motherboard, but I've read on a couple threads you can run two Nvidia GPUs in NON SLI with one card in x16 the other x8. I wish to use both cards in one computer for Fold@Home. Since they are both built on the 200 series I figured they would be compatiable in non SLI. So, I installed both cards and the computer booted fine but the GTX 275 in the Device Manager reports:

"Windows has stopped this device because it has reported problems. (Code 43)"

I have tried switching the boards around, tried installing the previous drivers, used Drive Sweeper and reinstalled drivers, but to no avail.

The strange part is that my computer will run perfect hooked up to the GTX275 hooked to the monitor with a working display EVEN with the error and the GTX260 reporting fine.

And no matter what I have changed the error only occurs with the GTX275; which does function fine solo.

Any solution or suggestion is much appreciated.

ToBXaH

BTW I won the GTX 260 so I never purchased different cards intentionally.

[Psycho101]

May I ask which version of Windows you are using?

If you completely remove the drivers and let Windows install the bog standard VGA ones, do you get the same problem?

[ToBXaH]

Windows 7. Yes, the auto install default drivers were bogging it down too.

I may have solved the problem though, after numerous tests with different systems I came to the conclusion my GTX 275 had died.

I have RMA'd the card and hopefully will have it functioning soon.

Update in the near future.