GTX 295 Slows PC to a crawl when second card added.

I am having a problem that I can't quite wrap my head around. So I am finally giving in and asking for help. I have two ASUS GTX 295's that I am attempted to run in a quad SLI setup. The system runs fine with one card installed. When the second is installed it slows the entire system down to a crawl. Here is my setup.

Motherboard: ASRock x58 supercomputer
CPU: Core i7 920 Nehalem 2.66GHz
RAM: GSkill 6 x 2 GB DDR3 1600
Video Card: 2 x ASUS GTX 295
HDD: HITACHI 0A38016 1TB 7200 RPM 16MB Cache SATA 3.0Gb/s
Case: Antec 1200
Power Supply: Corsair 850 Watts

I have tried removing reducing the ram to 4 Gig.
I have tried Updating to the newest drivers for the video card and motherboard.
I do not know much about the settings for RAM in Bios so I have not changed any of those other than to verify that they are running at 1600 DDR3.
I have tried XP pro, Vista 64, and UBUNTU.
Strangley when running that windows performance rating in vista it rates the ram as a 1 with both cards installed as opposed to a 5.9 when it is runnin with one video card.

This is my first SLI setup. Please any help or ideas anyone could give me would be greatly appreciated.
7 answers Last reply
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  1. Check this out. Turns out that adding a second card can actually slow down some games, and overall is not worth the money at this point. Sorry! Must be nice to have money to burn. Please send me your second card. ; ^)
  2. The problem is actually with slowing down everything not just games. Makes the system act like it has 256 MB ram or something that is how it feels at least. It takes like 7 to 10 minutes to boot into windows.
  3. If it were me it would be as though ur system aint getting the power it needs for a second:D haha

    I would say its a coincidence, and it could be a virus. THe 850 PSU seems kinda risky for such a setup though....

    Did you try removing the 295 GTX and seeing how it does with out it?

    If that solves the problem I would recommend returning the card, and staying put till better drivers are out, and you get a new psu:)

    The yields from adding a 2nd card for quad sli are sometimes worse than 0...
  4. To me, it sounds like the PSU isn't enough, I believe the requirements for quad sli GTX 295 is 1000W minimum and 1200 watt recomended. However having said really isn't worth it to quad sli gtx 295, the increase in framerates isb't worth it, I am running one gtx 295 and from what I have read 2 just aren't worth it for the bang. I am not sure but I figure it might have something to do with the 295 basically being sli'ed internally 2 cores and whatnot and to take advantage of 2 of those just is more than the drivers are really capable of right now.
  5. I second that Jake. The 850W you are using is not enough...
  6. +1 to PSU get 1000w+ PSU.
  7. already answered...stronger PSU needed
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