Hi,

My new system comprises of the following :

Intel Quad Core Q9550 CPU
XFX 790i Ultra Mainboard
Thermaltake Tough Power 1000W PSU
Coolermaster Cosmos S Case
Corsair 4GB DDR3 RAM (2x2GB) (TW3X4G1333C9DHXG)
2 X BFG 8800GTS 320 MB VGA cards
Soundblaster XiFi Platinum Soundcard
SATA DVD-ROM Drive
SATA DVD-RW
WD 320GB SATA II HDD

The system sporadically resets, there is no blue screen at all, no messages in event viewer. It can take up to a few hours to reset.

I have witnessed it whilst running Memtest x86 so I am confident no SW is involved.

What are the most likely causes for such an issue ?

I have removed the soundcard and used onboard audio to no avail.

I have loaded BIOS defaults, no joy.

I am running RAM at 1333MHz and FSB at 1333Mhz. I found that this would only pass memtestx86 with the RAM voltage at 1.675V. Does this sound about right ?

I do not think that when it resets in Memtest x86 it is down to the memory settings, I think the root cause is something else but I may be wrong.

Would adjusting CPU and FSB voltages be a potential root cause ?

I have currently removed one VGA card and am now testing. I did have each VGA card plugged into its own dedicated rail on the PSU when both were in.

Any suggestions you can make would be much appreciated. Thanks in advance.

Cheers

1. Motherboard - There is a reason we recommend Intel chipsets on these boards

2. PSU - While not the worst choice in PSUs, any PSU can be bad. A bad overvoltage sensor could cause a reset.

3. - Some random short. Make sure you don't have any standoffs in the wrong place under the motherboard... they should only make contact where the screw holes are.

You could certainly try stripping down the build to the basics... one stick of RAM, one video card, no optical drives, and see if that solves anything.

Discovered one of the RAM modules is faulty. Got replacements on the way.