Here are my specs,
power supply= Coolmax 850w
Asus P5N32-SLI SE Deluxe ( Latest Bios )
Intel Core2 Duo 2.66GHz
2 X ASUS 7950 GX2 Video Cards
2 X OCZ PC2 6400 Patinum memory 1GB
4 x 149 Gb HD RAID 5 SATA
Sound Blaster X-Fi Fatality Champion Edition
ASUS DVD Drive
nForce Version 15.23
Display Driver nVidia 190.62
Ok , both video cards work fine seperatly from each other but as soon as i try to Quad SLI them the system will stay running but if i go to any 3D app it hard lock the computer. All the hardware i have is on the qualified list for Quad SLI. What am i doing wrong!!!!
That must have been one hell of a system back in the day... and while I do agree that all of your specs suggest you SHOULD be OK... the reality is that you're having trouble with a 4 GPU setup that is basically matched in performance by a single GPU (5870!) without any of the hassle of a multi GPU setup. I doubt I'll ever have a multi-GPU setup just out of fear of compatibility/stability/performance/driver issues. Unless you're using top-tier GPUs, I really don't see the point. Ok, I'm done with my rant so here's my only suggestion...
It could be a power problem. Although you didn't list your exact model (that manufacturer apparently made multiple 850 watt units), I'd be willing to bet your PSU has multiple rails (likely 3 or 4) ... is there a chance you have your two video cards tapping into the same rail? It's just a thought. I know you said that both cards are OK when operating independently, but only when gaming in quad-SLI will you fully tap into their power... so when you're just gaming on one, the other card is just idling and drawing considerably less power. Rails. That's all I got!
I agree with rodney_ws that a single card configuration is the best way to go unless you have a lot of dollars and yo uspend them all at once on the best cards out at the time. I think you would have less power draw and much better performance even with a single GTX 275 over those two cards. I would post those two cards on Ebay and get the money you need to get the single GTX 275 and it should run on your power supply just fine, remember I said "should" and I'm pretty sure I'm right.
You should easily get 100, maybe 125 max for each card. I would do that in a heart beat. I had 3 8800GTX ACS3 video cards pounding on my Corsair 1000 watt psu and burning my legs up during game play. I sold all 3 for 380.00 on ebay and got a single GTX 275 that rivals the performance of all 3 of those cards with no overheating and obviously much less power draw. I don't regret it for one second!!...
Well I have had some success! i had to go back to old drivers ver 175.19 it has worked in winXp 32bit and now i am getting some succes with same version Vista 64bit...
Some things i did:
uninstalled any and all nvidia software accept for the nforce 4 6.05.
Tried about 8 different versions of the drivers.
Determined that the newer drivers just do not work.
And finnally i agree i would love to have a new video card, short story; i bought my first 7950 GX2 when they released the Card. I have loved the card ran all the games on almost max setting untill Oblivion came out. Then had to throttle her back. Got a great deal on second card $75 for an ASUS 7950 GX2 that matched my first one which i paid $500 and some change OUCH!!! so i figure what the hell lets Quad this baby.
I knew Power would be a big issuse with Quad SLI and running raid 5 so forth and so on but its not the issue. The issue is drivers!!
Thanks for the input i still have not actually got to run a game yet, but tommorrow i will, Or maybe tonight if i can kep my eyes opoen that long..
I can understand the bond with the 1st video card. As silly as that sounds I still have my 1st 8800GTX ACS3 card I paid 600.00 for even after selling the other 3 I had. I am using that one in my media center pc and it's not going anywhere, lol.
Glad to see you are making ground. Let us know how the game plays...
Game are unbeliveable played Oblivion, Prototype, D&D online, and Warcraft online @ 1600x1200 with all graphics maxed out and was smooth as a babys bottom. I could probally go higher with res but monitor might have issues. I heard back from NVIDIA about my issue they have been no help yet they had me try the same version of drivers i have already tried exept fo some o fthe beta ones..