Stable 790i, Quad-SLI config - does anyone have one?

[Trailerman]

Hi

My system builder and I are putting together a 790i machine with 2 9800 GX2's, and we are having a nightmare trying to find a stable configuration.

We've tried both the Asus Striker II Extreme and EVGA 790i boards, different power-supplies, swapping memory etc., but are unable to get a system which gets much beyond booting without blue-screening. Spec is:

Intel QX9770
Asus Striker Extreme II / EVGA 790i (we've tried a couple of each)
2x XFX 9800 GX2
4GB Corsair DDR 3 RAM
Various DVD drives (we've tried a bunch)
2x 1GB Samsung SATA hard drives (non RAID)
Windows Vista 64bit
Air cooling


With one graphics card we can get the system stable. If we disconnect all the SATA DVD drives we can get it stable. Even without overclocking, and with the graphics cards underclocked, we canot get the full config to run reliably - blue-screens pretty much all the time. Temperatures are not the problem - very low when idle and pretty low under load.

Has anyone built a stable 790i SLI rig, or know of a spec' which is supposed to be stable, because we're pretty much out of ideas?

Many thanks for any help

Jules

 

[Granite3]

These guys did, and they tortured the board-

http://enthusiast.hardocp.com/article.html?art=MTQ4NCwxLCxoZW50aHVzaWFzdA==

Partly based on that review, I ordered an eVga 790i, to put my q9450 and my 2 8800 GTX's.

My guess is the 9800 Gx2s are your problem.

And/or the Ram, specifically the voltage.

What speed is the ddr3 stuff set?

The bios gives you the ability to "unlink" the ram and the fsb, was a sticky widget for me untill I discovered it on my 680i back when.

 

[Trailerman]

Many thanks for the link. We haven't tried the XFX mobo yet - I'm pretty sure it's a refernece design, very similar if not identical to the EVGA board we've been testing, but may be worth a shot.

The system is now all set at stock speeds - we took all OC'ing off to eliminate that as a factor - and it behaves the same.

I'm starting to think it may be a combination of the QX9770, the 64bit OS and early Quad-SLI driver issues. I'm yet to see any reviews which feature this combination, so perhaps there's something going on that Nvidia hadn't anticipated ....?

Thanks again

Jules