HD 4870 x2 Reboot problem

[synnk]

Ok so i recently bourght a new machine for £1100 and decided to go with the ATI HD 4870 x2 gainward. Normally a Nvidia fan i wanted a change.

I got everything working fine, until i started playing my games. My game will load up but within minutes my computer restarts itself with no error or screen freezing, its as if someone has pressed the restart button. I don't get any error message when i get back onto windows.

I am not narrowing the problem down to the GPU but as it only happens when i play something graphicly demanding i am assuming it is my GPU.

Setup

Intel Quad CPU Q9550 @ 2.8GHZ
3GB 1600MHZ DDR3
Windows Vista 32bt Ultimate
ATI Radeon HD 4870 x2
P45 Diamond Series MS-7516 Ver 1.0
Sata Hitachi SCSI 500Gb
PSU 800W Ezcool

GPU temp = 45c Idle
CPU temp = 35c Idle
Systemm temp = 30c Idle

Ive tryed the latest drivers and older versions. I know i have the latest drivers for all my other hardware. i just can't seem to find the problem Please help.

 

[juliank]

Hi, did you ever get your problem sorted out?

I have the same problem. Just bought a pc over the weekend:
Intel P45 Skyberg Mobo
E7400 Core Duo 2.8 Ghz
2x 2GB DDR 3 Ram
Sapphire Radeon 4870 x2 2GB
320 gig Sata HHD
730 Watt power supply

I'm running windows xp 64 bit and when I run games in full graphics the pc resets (it turns off and then back on) either just after I change it in the game menus or just as it starts to load. I’ve tried it in a few games – same problem.
I’ve taken it back for people I bought it from to sort out. I can think of a few reasons why it is doing this:
Faulty power supply, incompatibility with mobo or CPU, BIOS needs an update or there is an issue with windows xp 64 bit. I know it’s not a faulty card as the company I bought it from tested another 48070 x2 card in my pc and it gave the same problem. I downloaded the latest windows 64 bit catalyst drivers – didn’t help.

I have no clue what to do and I’m only posting this to help speed up the repair time. HELP ME PLZ