3-Way SLI Is Here In A Big Way - Real Gameplay Tri-SLI Testing

Article Index
3-Way SLI Is Here In A Big Way
TRi-SLi and 8800GTX Action
TRi-SLI System Build and Testing
Real Gameplay Tri-SLI Testing

Real-World Gaming:

Even though the 3-Way SLI shows some promise in a synthetic benchmark, we still wanted to see what it was like in some real-world applications that rely on CPU power for AI, audio processing and more.  3DMark 06 doesn't analyze that in the default benchmark so we decided to run Call of Duty 4, Call of Juarez DX10 Demo, Half-Life 2: Episode 2 and Unreal Tournament 3 to see how these games all stand up.  I know that some of you are wondering why we left out Crysis, but currently Crysis doesn't like 4GB of RAM on any of our test benches and running 2.2GB of Video RAM with only 2GB of RAM doesn't offer valid scores.  We hope to update the results with Crysis scores once we can get 4GB running stable under Crysis.

We're going alphabetically, so the first one us is Call of Duty 4.

Call of Duty 4
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Our game play performance was take from the level Heat and involved a lot of explosions, machine gunning and intense battle out doors on a lush hillside.  We recorded the frame rates with FRAPS and repeated each run through several times for consistency.  This gives you actual game play numbers that you can compare with on your own machine.  Everything was set to high at all times with 4x AA enabled. With such high detail, a single card can barely keep up at 1920x1200 and adding the second card for traditional SLI gives you a boost of 1.45x and makes the game very playable with an average of 55FPS - up from 38FPS average.  When you drop in the third card, you can an additional 20 frames per second and boost your performance to 1.97x that of a single card.  The big news is that you only get a 17FPS boost with two cards and get 20FPS with three cards.


Once we move to 2560x1600, the second card gives us 20FPS gains which total 1.69x that of a single card.  Dropping in the third card yields another 15FPS for a total of 2.21x that of a single card.  In this game we see very acceptable gains for the third card.  Let's move on to the DX10 benchmark of Call of Juarez and see how things hold up.

Call of Juarez DX10
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In Call of Juarez, we ran a large shadowmap size, normal shadow quality and 2x AA.  This demo only supports resolutions up to 1920x1200 so we ran 1680x1050 as well as 1920x1200 for comparison.  A single card struggles in this DX10 demo and the best we can do is average 20.6 at 1680x1050.  A second card gives us 1.66x performance at this resolution, and 3-Way SLI jumps up the performance to 2.61x a single card.  At this resolution we see the 3-Way SLI really perform well - much better than I was expecting.  With such a "low" resolution of 1680x1050 behind us, we now jump into 1920x1200.

With a single card installed, the demo chugs by at a measly 18.2FPS.  Adding a second card made it almost bearable at 26.7FPS average - a performance increase of 1.47x.  When adding the third card for TRI-SLI, it managed to pull off an average of 36.2FPS and was almost pleasant to watch.  The third card pulled a boost of 1.99x.  Although it was a little weaker than the lower resolution, it still has a nice showing at this resolution.

Moving on to Half-Life 2, we chose to use Episode 2 as it has more detail, better lighting and more effects than the earlier versions.  That being said, the game still runs very well and is a credit to the hard work that Valve put into this game.  We ran at both 1920x1200 and 2560x1600 at maximum detail and 4x AA.

HL2 - EP2
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Half-Life 2 ran very smoothly at 1920x1200 on a single card and averages an impressive 66FPS.  Doubling up the graphics power only yielded an additional 9FPS which translates to a mere 1.14x.  When we dropped in the third card we say the performance actually go up quite dramatically and we averaged 104FPS - 1.58x a single card.  Nothing to brag about, but for a game that already runs great on a single card at 1920x1200, it's a nice improvement.  Moving to 2560x1600 we retested to see how things performed at 4 mega pixels.  Any game at this resolution looks impressive and HL2:EP2 is no exception.  A single card still managed an acceptable 45FPS, but here we see a 1.31x improvement when running a second card.  The third card gives us a 1.93x improvement.  As resolutions rise, so does the benefit of $1800 worth of video cards.



Finally we take a look at UT3.  While many say that this game is merely a warm-over of the previous versions, the truth is that it is filled with HDR Lighting, shaders and a lots of soft particles.  It runs well on older hardware when scaled down, but when running at maximum detail at high resolutions, it can bog down a high-end system.  In this game we left everything at maximum quality and disable "framerate smoothing" which removes the games 60FPS cap.

Unreal Tournament 3
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This game performs quite well at both 1920x1200 and 2560x1600 with a single card, and we don't actually see tons of improvement when we double and triple up the SLI.  That being said, we still see a 1.23x improvement at 1920x1200 when going with traditional SLI, and a 1.35x improvement over a single card with 3-Way SLI.  The truth is, even with the game maxed out at 1920x1200 - a single card is good enough.  2560x1600 is a little different story though.  At this resolution a single card averages 47FPS, and while that may be fine for a single player campaign, when playing multi-player the frame rates at times get into the 30's and this can be a little difficult when trying to dodge away from BoneRak on Deck.  SLI helps things out and brings our average up to 77FPS - an improvement of 1.64x.  Adding the third card only brought up the Average FPS to 83FPS - 1.77x a single card.  This third card didn't offer really noticeable performance in-game and if you weren't benchmarking, you likely wouldn't see any improvement.



Final Thoughts:

After spending a few weeks with the 780i SLI platform and having some fun with the 3-Way SLI from nVidia, it is actually a bit disappointing to run only a two-card SLI setup again.  Not that I need to have three cards in a system for the amount of gaming I do.  In fact, no one "needs" 3-Way SLI.  The truth is, 3-Way SLI is downright awesome though.  To put three cards in a system, draw over 700W from the tower alone and play games at maximum detail at 2560x1600 is a wonder to behold.  The platform is stable, has great driver support and was absolutely painless to setup.  Really, there is nothing bad to say about it - other than price.  If you already have a 680i SLI board, it is supported but you will still need to grab the large 3-Way SLI bridge and that isn't available at your local Fry's or Newegg.  Not to mention you'll need yet another 8800 GTX or 8800 Ultra graphics card and should have a 1000W PSU to ensure stability.  If you are running a mid-range dual core processor, you'll be sorely CPU limited and you should have at 30" 2560x1600 display to really enjoy your pile of graphics processing power.  All-in-all, it's a very expensive platform to buy into straight up, but in my honest opinion, it's worth it if you've got the cash and enjoy gaming is Super HD.

The big question I have is will nVidia enable 3-Way SLI on other cards and how long will this platform be supported?  The 7950GX2 lived a short life with this "Quad-SLI" offering that wasn't supported very well or for very long.  I would be a bit wary of nVidia pulling the pin on this platform once the next generation of their graphics cards comes out.  If they stay true to form, a single 9800 GTX will perform very closely with 8800 GTX SLI, so it may be worth it to wait.  If you can't wait, you'll be ROFLMAO as you pull 64FPS in CoD4 at 2560x1600 with 4x AA and everything cranked to the max.



  • Excellent driver and game support
  • Quiet performance with stock coolers on cards
  • Nice performance scaling with additional card
  • Looks darn awesome!



  • Expensive platform
  • Heat could limit graphics cards life as they are so close to each other



I'd like to thank MemoryExpress for setting us up with the hardware we needed for this review and for Astrofox for pulling his own card to help us make this happen.  It was fun, interesting and nobody got burned by the cards!

Please post your comments, questions and feedback to this review at the "Comments" link below.