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Old 02-05-05, 11:54 PM   #3
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Join Date: Mar 2003
Location: Tulsa
Posts: 5,101
Default Re: Nvidia SLI Investigation.

Gaming Performance

Test Setup and benching methodology: My benchmarking methods are typical to prior benchmarks done by me. I use fraps and record 3 preset runs through a standard level in each game illustrated. I then divide the results by 3 to reduce margin of error. Margin of Error is usually with 1 FPS and I take great pride in the accuracy of my benches.

Athlon 64 3800+ @ 2.4 Ghz
Asus A8N SLI Deluxe
1 Gig DDR400 (Dual Channel) CAS 2.5
Dual 6600GT's


Nforce 6.39 Platform Drivers
Nvidia 71.80 Display Driver

Far Cry

Far Cry: The performance benefits to SLI will just jump out and strike you. The performance increases took settings that were unplayable on a single GPU to levels that were smooth and offered an enjoyable playback experience.

Nvidia optimised Profile

Doom 3

Doom 3: Unless you have been living under a rock without an internet connection. You probably know that Doom 3 has been one of the most demanding games released this last year. Bringing last years graphic cards to there knees. It is also optimised to take advantage of Nvidia hardware. One thing that should be noted. Disabling AA brings about substancial performance gains. This is probably due to the way anti aliasing effects two sided stencil acceleration and the 128 framebuffer limitation of 2 6600GTs.

Alternate Frame Rendering Profile

Everquest 2

Everquest 2: Quite possibly the most demanding MMORPG ever released. This game is known for bringing the most high end computers to their knees. Adding a second GPU does seem to benefit the gameplay experience. But the platform still remains remarkably CPU bound and minimum framerates dont seem to be affected.

Note: Everquest 2 is currently only SLI compatible with 71.80 drivers. It has a custom profile for them. Forcing SLI with earlier drivers will cause rendering errors and crashes with EQ 2. T

Nvidia optimised Profile

Call of Duty

Call of Duty: Call of Duty starts out CPU bound even on a single GPU platform. As expected from the earlier aquamark results. When you are CPU bound SLI creates a slight CPU overhead which is slightly detrimental to performance. Once the resolution and anti aliasing has been increased the benefits of SLI become readily obvious however. Call of Duty is not by default SLI enabled. I had to force AFR mode with application listed in the first post.

Alternate Frame Rendering Forced Profile

Half Life 2

Half Life 2: Half Life 2 also started out CPU bound. As with other CPU bound situations it proved to create a slight CPU overhead. As with Call of Duty enabling higher levels of resolution and anti aliasing started to show the benefits of SLI however.

Nvidia optimised Profile


Conclusion: SLI has a lot of potential. At the moment it can be seen in just about every GPU limited enviroment. CPU limited enviroments will probably not benefit much from it however. Considering all the talk about Nvidia profiles I expected limited application support with SLI. However thanks to enthusiast users and the ability to edit the profiles. I havent found any real problem enabling SLI in any of my favorite games that do not already support it. I do hope Nvidia listens and adds an "Advanced" tab that allows users to switch SLI on and off via the control panel. The current method isnt what I'd call the perfect solution. Fortunately issues such as this can be fixed with driver updates. Given the the need for the profiles I would hope Nvidia steps up and increases there regular driver updates to meet the demands of the new SLI profiles they have developed.
|CPU: Intel I7 Lynnfield @ 3.0 Ghz|Mobo:Asus P7P55 WS Supercomputer |Memory:8 Gigs DDR3 1333|Video:Geforce GTX 295 Quad SLI|Monitor:Samsung Syncmaster 1680x1080 3D Vision\/Olevia 27 Inch Widescreen HDTV 1920x1080

|CPU: AMD Phenom 9600 Black Edition @ 2.5 Ghz|Mobo:Asus M3n HT Deluxe Nforce 780A|Memory: 4 gigs DDR2 800| Video: Geforce GTX 280x2 SLI

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NVIDIA User Group Members receive free software and/or hardware from NVIDIA from time to time to facilitate the evaluation of NVIDIA products. However, the opinions expressed are solely those of the members

Last edited by ChrisRay; 02-19-05 at 06:59 PM.
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