Testing SLI

**Cjl64** · 11-11-2007, 08:39 PM

Okay.. well i am currently running my system in SLI. My buddy got tired of trying to get his 2 8800GTX's to actually improve frame rates. So he asked mt if i wanted to use his other 8800GTX for a while for test and what not.... i was like ummm.. hell ya. Okay... so i have it all installed with the bridge on the bottom 2 connectors and all. I activated SLI in the control panel like recommended. So i am all set.. i used lost planet as my reference game for testing SLI because it was the first game i knew i could FPS test easily anough and i heard it scales with SLI.

Well so far i also find that SLI does nothing to actually increase performance. Some of my test show me loosing FPS with SLI. This is what my buddy also went through. He also went through 2 new cards and a mobo trying to resolve this and still nothing. I guess my question to you guys is... how can i test to see how SLI actually helps anything.

I have ran a few other games also. tried the split frame, alternate frame 1 and 2 and single GPU both in the game profiles and global settings. I get mixed results.. but none are faster than SLi disabled.

Check my sig for details... its not the PSU because the Corsair 620HX is very solid and can handle 2 8800GTX's.

Okay.. well enough for now... i hope some of you can give me a little direction.

**SirBaron** · 11-11-2007, 08:55 PM

Alternate Frame Rendering 2 should only be ever used, pretty much no game works with split frame.

What settings are you trying to use SLI at? 1920x1080 if i remember is your max resolution (like me now). Sooo try playing Lost Planet (and make sure multigpu is selected in the options of the game) and play it at 1920x1200 8xAA/16xAF and do a fraps benchmark with SLI on and off.

HOWEVER i have heard that SLI support on Windows Vista 64bit is a hit and miss, so if you're using that it could be one of the problems.

**Cjl64** · 11-11-2007, 08:59 PM

Originally Posted by SirBaron

Alternate Frame Rendering 2 should only be ever used, pretty much no game works with split frame.

What settings are you trying to use SLI at? 1920x1080 if i remember is your max resolution (like me now). Sooo try playing Lost Planet (and make sure multigpu is selected in the options of the game) and play it at 1920x1200 8xAA/16xAF and do a fraps benchmark with SLI on and off.

HOWEVER i have heard that SLI support on Windows Vista 64bit is a hit and miss, so if you're using that it could be one of the problems.

Maybe it is the OS. we both run Vista 64bit. I am at work now... but i am going to be testing the card for a while i guess. When i get my new 500GB HD i am going to reformat and maybe load vista 32 up and try it again with the 32bit OS.

I will post back if i find an results.

**SirBaron** · 11-11-2007, 09:00 PM

Originally Posted by Cjl64

Maybe it is the OS. we both run Vista 64bit. I am at work now... but i am going to be testing the card for a while i guess. When i get my new 500GB HD i am going to reformat and maybe load vista 32 up and try it again with the 32bit OS.

I will post back if i find an results.

Hope you fix it, as when it works, you're glad it does (crysis)

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**Cjl64** · 11-11-2007, 09:17 PM

Originally Posted by SirBaron

Hope you fix it, as when it works, you're glad it does (crysis)

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What settings did you use the get SLi to work in the demo?

**SirBaron** · 11-11-2007, 09:20 PM

Originally Posted by Cjl64

What settings did you use the get SLi to work in the demo?

Alternate frame rendering 2, (Nvidia auto selects the best setting in each game profile anyway) providing you have the latest BETA's.

Though according to Nvidia SLI isn't working properly yet in Crysis. I imagine a new driver will surfice in the next few days.

**Cjl64** · 11-12-2007, 11:25 PM

i am still not sure if SLi is fully working.... but i did get Nhancer and played with those SLI options. Let me just say wow!!! i have never seen SLI AA before...omg!!! I tried the highest which is 64xSSAA something like that... i have never seen graphics so clean looking before. I was playing call of duty 4 and was surprised that frames where still playable with this level of AA. I did go down to 32QAA as that runs really fast and still looks really impressive. I cant wait to get back home from work and try these AA settings with other games. I will have to post some screens..... for real... the level of visual quality is insane!!!

**VW_Factor** · 11-16-2007, 05:28 PM

I find improvements ranging from like nothing to nearly 45 to 50% in cases. Depending on the game, and settings, etc..

Thus far Im very happy with SLI. Just glad that nVidia has stepped up on the drivers and help us out in that department.

**SirBaron** · 11-16-2007, 11:42 PM

Depends on the game Lost Planet and Call of Juarez being games where it's really easy to gain 100% increase in performance due to how GPU limited they are.