Hey everyone, this is gonna be an odd thread, but here goes:

I've recently bought a new machine (got it assembled in the shop) consisting of:
Intel C2Q Q6600 (2.4ghz)
Dual SLI 8800 GT 512mb
Abit nforce Fatality SLI mobo
2 GB Kingston DDR2-800 Ram
850W Gigabyte power supply
Windows Vista Ultimate (32-bit)
ViewSonic 28" amazing LCD

Updated every single windows and Nvidia drivers (169.25) I could find, and downloaded the patch for Crysis

Now when I started Crysis, I put on a mix of medium-high settings thinking wow, even with SLI this game is a monster. I benchmarked the GPUs and got around 26-33fps (this was still in 1280 x 1024)
Then I wanted to see how much SLI really did for Crysis, so I disabled SLI
And Voiala, 40-60 fps, thinking this couldn't be, i tried enabling and disableing SLI, restarting my pc, but no change.
Then I upped the settings to a mix of medium - high - very high (texture quality, water, physics, particle quality)
Benchmarking 1 card got an average of 36fps
Benchmarking SLI got an average of 10fps

My Gigabyte PSU has 4 thermometers so i connected 1 to each of the cards, but they had very similar temps running at full power so both were obviously working.

I was desperate so I swapped the cards, then took 1 out to see if it was a faulty card, but on their own, each performed perfectly. Pc could see SLI, and whatever config of the cards I tried, no improvement.....Then with both cards in, I took out the SLI bridge to see if that was the prob, and funny enough, the benchmark returned the same results with it out as when it was in. I went back to the shop and got the bridge replaced for another one from a same Fatality mobo but even with that I didn't get an improvement.

Oh, and I'm getting worse fps in other games aswell so this prob isn't a Crysis bug

I have searched the net for any other cases like this, but couldn't find any, and everywhere I went, SLI always rendered better results.... I just bougth the ViewSonic 28" LCD (btw it is frikkkkin amazing) and I really want SLI to work and run it at higher res (even now with 1 card setting things to a mix of med & high and texture quality to very high, at 1920 x 1200 I am still getting between 17-33fps). I'm lost for ideas so if anyone has a suggestion, pls post and help

Thx, Gellert

My question is, did you enable SLI in the BIOS? You have to enable it in the Nvidia control panel as well as the BIOS. I get 19.7FPS w/o SLI and 27.7 with at 1920x1200 all high. Also try increasing the resolution because SLI scales better at higher resolutions.

cooling issue

remove the door and blow a fan on it and test it

Its definitely not a cooling issue as im using it without the door and both cards remain under 46 degrees.

you answered your own question. Vista and Geforce.

As i know of, geforce and vista still having issues. Ati and vista seems to be much better. I think i saw a listing in this forum talking about it..

First off... I see your power supply. Still, it sounds like it could be a power supply issue since both cards under full load is slowing the system down. You could also try the latest Nvidia Beta drivers which are supposed to have improved SLI performance in Crysis (YES I saw that you're having the same issues with other games). http://www.nvidia.com/object/winvista_x86_169.28.html
Also, I know they came out some time ago and you probably already have them, but did you get the Microsoft patches they released to improve 3D gaming in Vista?

Also: not to be nitpicky, but it'd be a 28" monitor not a 28' monitor

-mcg

I can't find anything about the GPU in the BIOS, I have the latest version but it doesn't show anything about SLI settings, or any GPU related options...

thx for the beta driver, I d/l it but SLI still didn't get better
It looks like this is a hardware issue...

Are all of the power connectors..connected? You said you had it built at the shop, so maybe they overlooked it. One of my friends had a similar problem with Crysis. He connected the extra power and the results were amazing.

just wondering, why not take it back to the place that built it and have them deal with it?? I could understand if you built it, to have thease questions. But for having it built for you. I myself would just take it back to them with any game and show them whats going on.

did you connect an sli bridge. i know a lot builders around me keep the bridge. make sure your power supply has the rails to support sli im sure you got enough wattage

go here to calculate your wattage http://www.extreme.outervision.com/PSUEngine

i think sli will take up more of your system memory so i would upgrade the to 3-4 gigs. that speed ram is cheap now. 2 gigs for $45. a game like cysis needs a lot of ram. i would check the the amount of memory being used while playing crysis.

windows vista is a memory hog it takes up about 800-900 mb of ram on my system while idle. leaving only 1100mb for games and apps

I wanted to solve the problem at home cause the thing ways a ton, but looks like I definitely have to go bck...
Yes the power supply is SLI ready an is connected
Btw, system idle only takes up bout 600mb for me, and while in Crysis, it only uses bout 1700mb (at first I also thought it was RAM bottleneck)

It really sounds like a power issue, at least thats the way it apears. If your playing at 1280x1024 using SLI then that most likely would give you bad performance, SLI only starts to show its true power at or after 1680x1050. Theres probibly something you missed, maybe a setting in BIOS.

I've gone through the BIOS (latest version) and there is nothing regarding SLI or for that matter the GPU...
I'm playing in 1920 x 1200 now with my new 28" monitor, and with SLI disabled I get 33fps, whilst in SLI I get 12fps...
I used that power calculator cal posted, and I'm supposed to have lots of reserve, but thx for the input tho...

With my motherboard there are two settings SLI Broadcast Aperture and Nvidia GPU Ex, the first is set to Auto and the second to Enable. There should be some setting in the BIOS to enable SLI, I think you might be missing it.

Although I don't have an SLI / Crossfire board (but will soon) I also suspect that a bios setting has been overlooked regarding sli or speeds.
Is there a setting in bios to adjust the speed of each slot? Are they both set to run at 16x or whatever?
Just a thought.

The 16x and whatever x slots usually are color coded, in my case the 16x slots are blue and the 8x slot is white. I think it's a BIOS issue he is overlooking.

Look at my sig, there isn't a problem with Vista and Geforce.

where in BIOS exacty do you have these SLI settings?
all I have under "advanced chipset features" is:
Memory Timing Setting <press Enter>
SLI Broadcast Aperture <Auto>
LDT Frequency <5x>

Btw, wut is "PCI/VGA palette Snoop"? lol

Have you installed any forceware/chipset drivers yet? When I say forceware I mean motherboard/chipset drivers and not forceware drivers for your graphics card.