I am running two EVGA 8800 GTX cards in SLI mode on an EVGA 780 motherboard. The cards work well when I use them with FS9 on either XP or Vista 64, and also well with FSX on XP or Vista 64. However, when I run FSX on Vista with the DX10 preview boxed checked, my computer crashes and I get the dreaded blue screen of death.Is this happening just on my system or have others had this problem? If so, is there a solution?BillCPU: QX9650Motherboard: EVGA 780RAM: 4096 (800Mhz)Power: 700 WattHD1: XPHD2: Vista 64HD3: StorageHD4: External Storage Drive

I have 2 8800GTX's in SLI mode with the NVIDIA 680i SLI motherboard. I have never had a CTD/BSOD with DX10 Preview enabled. I do have 1KW power supply and that may be the reason for your crashes. Have you ever looked at the Event Viewer to see exactly what caused the crash? Was it related to an Nvidia display driver (it will show you what program or file caused the crash)? That's what you should find out first and then maybe someone can help. A bad installation of display drivers has been known to cause BSOD's/CTD. There was also a March update of the DX10 files and an update to Vista (to SP1). If you haven't already, you should get those updates and see if that fixes your problem. There are different Nvidia display drivers for XP and Vista and I see in your post that you covered all bases to show your video cards work okay using the XP OS and FS9 with Vista 64. It's strange it crashes only when DX10 is enabled. Could it be your HD/FSX/FS9 configuration? Perhaps FSX is not reading your FSX.cfg correctly. You certainly have quite an interesting configuration... In any case, it's not a FSX problem or else everyone who had FSX with DX10 enabled would be getting a crash and that's not happening. Lot of happy campers out there!Ciao,Jim

I agree that 700W seems on the low end for two high end video cards and the 9650. The chip itself should be ok, it's the rest of the board I'm worried about. Don't know how well your power supply holds up under load (not all power supplies are created equal). By my count, each card is at least 250W each under load, plus another 125 for the CPU, and depending on how many peripherals you have, that leaves very little "wiggle room".Can you share more about your hardware, such as memory and chipset? I would count 300W per video card, and 200W for the motherboard and CPU min (a 45nm chip consumes less, I know, but you do have 4 cores).Then again, DX10 in SLI mode is also a shot in the dark given how few titles actually support DX10. Do you have Crysis by any chance? I'd give the demo a whirl if you don't, and report back if you get a blue screen.Also, can you run prime95 multithreaded on 4 cores with no issues? Do you overclock your 9650?Regards,Etienne