Ok, first I know I need to do a bit more troubleshooting here but hoping someone may be able to direct me where I need to focus on.
First my setup:
MB: Gigabyte x48-DQ6
CPU: Intel e8500
OS: Windows Vista 64bit
Ram: 8GB ddr2
PSU: Toughpower 700
I recently upgraded my 8800gts to the sapphire 4850x2 card. The old card was starting to just stop displaying anything to the monitor, though sound and such was still working, whenever I was gaming.
When I installed the new card I removed the nvidia software and booted up in safe mode and ran drive sweeper to complete the removal of all files. I then booted up with the 4850x2 card in and installed the drivers that I downloaded from Sapphire (the 8.12 version) and was up and running.
I played several games for a while and didn't seem to have any problems. However when I am in World of Warcraft for about an hour or so, it suddenly will just lose complete power and my ssytem is rebooting. I even rolled back to the 8.11 drivers but seems to keep doing this. The card does not appear to be overheating.
What I'm starting to think is its the pcie 6 pin cord from my power supply is failing. On the 8800gts, it fails out and the card just stops responding but on the 4850x2 the failout causes a critical error and the whole system reboots.
Anyone have any ideas if my assumption is correct or if I need to look in some other direction?
I don't think it's a PSU issue, the toughpower is a good one and 700 watts is a lot. The only power-hogger in your system is the 4850x2. I would try underclocking it by 100MHz then if it works you know it's a problem with your 4850x2.