SLI problem

[Piekku]

I decided to get another gpu for my rig, the one I had already being gigabyte gtx 280 and the one I bought being MSI gtx 280 super oc, and once I got the system running, it has been crashing usually always after a cold start (computer kept shutdown for more than half an hour). By crashing I mean screen freeze. The picture just stops and at first the sounds go abit weird but after a while the sounds come back to normal but the computer itself is stuck. I have to shut the computer down and take the power off from the PSU. That fixes it untill I shut the computer down again for more than 30 minutes. I have tested both cards independently with OCCT, got no errors from memory and ran the gpu test for 1 hour straight and the temps stayed at 85C and no errors. Is it RMA time for the gpu I bought or could there be something else causing the problem? Haven't had any such crashes when I was running a single gpu setting. Done clean install on graphics drivers, used driver sweeper etc. using the newest nvidia drivers. Had the same problem with every driver I have tried. Also tried another sli bridge and still has the same problem... should I try to upgrade the mobo bios or/and gpu bioses? or is/are one of the cards/both cards simply faulty?

system specs:
cpu: AMD phenom x4 9950 BE @ 3ghz
psu: corsair hx1000 sli ready
memory: 4g OCZ ddr2 pc2-8500 1066mhz sli ready
gpus: gigabyte gtx 280 + msi gtx 280 super oc
mobo: crosshair II formula nforce 780a sli
hd: seagate barracuda 7200 500gb

[absic]

Hi,

Not sure where I read about this kind of problem (maybe somewhere on this forum) but the issue was traced to the memory speed of the GPU's. When the OC'd card was stepped down the problem disappeared.

Is it possible that this is the cause here? You are running 2 cards with different specs and it could well be a memory rating issue.

As you have tested both cards without any issues be throwing up until you combine them this is the first place I would be looking.

ATB

[Piekku]

so you're suggesting downclocking the factory oc'd card? I'll try that

[absic]

Hi,

Yes, downclock the MSI card to the same rating as your other card.

Sorry I can't give link to where I picked this up from. I will keep looking and once I have tracked it down will post back.

ATB

[Piekku]

which software should I use to do this? the nvidia ntune thing doesnt seem to save the downclock

[absic]

Not sure about that as I use ATI cards myself. I know this is frustrating and you want to get an answer but I honestly don't know and you could be waiting a while before anybody else on the forum can answer that question for you.

As you are using an ASUS Mobo do they have a utility to allow you to do this? Like Gigabyte's Easytune Software

Any possible help from your posting on the MSI website? (I've been browsing for help with your problem and came across your posting there!)

I'll keep looking for you but...... 

[Piekku]

I found a way to save the downclock profile so that it loads at windows startup