NVIDIA GeForce 8800 GTX SLI Performance Review
System Setup and Benchmarks Used
Requirements for 8800 GTX SLI
Obviously, seeing as the 8800 GTX card used a lot of power in our first tests (though not as much as originally predicted before launch), I knew going into this that an SLI configuration was going to require a hefty power supply. Since I just so happened to have one of the PC Power & Cooling 1 kW (1000 watts) power supplies sitting around, I decided that would do the trick!
Retailing for about $599, this is definitely not a cheap power supply. But if you are looking for a unit that is going to keep your system running stable no matter the components you put in it, this is it. But the main feature about the PC P&C 1kW that makes this unit ready for SLI 8800 GTX is that it has four 6-pin PCIe power connectors on it.
Since each 8800 GTX card uses two PCIe power connectors, for running two of them you'll need four connectors. There aren't many power supply options that have four PCIe connectors, but another option is the Silverstone Zeus ST85ZF 850 watt power supply that our very own Lee Garbutt reviewed recently. Both should work fine, and with the Silverstone unit priced under $300, it definitely has a price advantage.
Here is a picture of the two 8800 GTX SLI cards running on the EVGA 680i motherboard that was released the same day as the 8800 GTX video card. A Sound Blaster Audigy 2 sits between the two graphics cards, all being controlled by an Intel Core 2 Extreme X6800 processor at 2.93 GHz.
Graphics card testing has become the most hotly debated issue in the hardware enthusiast community recently. Because of that, testing graphics cards has become a much more complicated process than it once was. Where before you might have been able to rely on the output of a few synthetic, automatic benchmarks to make your video card purchase, that is just no longer the case. Video cards now cost up to $500 and we want to make sure that we are giving the reader as much information as we can to aid you in your purchasing decision. We know we can't run every game or find every bug and error, but we try to do what we can to aid you, our reader, and the community as a whole.
With that in mind, all the benchmarks that you will see in this review are from games that we bought off the shelves just like you. Of these games, there are two different styles of benchmarks that need to be described.
The first is the "timedemo-style" of benchmark. Many of you may be familiar with this style from games like Quake III; a "demo" is recorded in the game and a set number of frames are saved in a file for playback. When playing back the demo, the game engine then renders the frames as quickly as possible, which is why you will often see the "timedemo-style" of benchmarks playing back the game much more quickly than you would ever play the game. In our benchmarks, the FarCry tests were done in this matter: we recorded four custom demos and then played them back on each card at each different resolution and quality setting. Why does this matter? Because in these tests where timedemos are used, the line graphs that show the frame rate at each second, each card may not end at the same time precisely because one card is able to play it back faster than the other -- less time passes and thus the FRAPs application gets slightly fewer frame rates to plot. However, the peaks and valleys and overall performance of each card is still maintained and we can make a judged comparison of the frame rates and performance.
The second type of benchmark you'll see in this article are manual run throughs of a portion of a game. This is where we sit at the game with a mouse in one hand, a keyboard under the other, and play the game to get a benchmark score. This benchmark method makes the graphs and data easy to read, but adds another level of difficulty to the reviewer -- making the manual run throughs repeatable and accurate. I think we've accomplished this by choosing a section of each game that provides us with a clear cut path. We take three readings of each card and setting, average the scores, and present those to you. While this means the benchmarks are not exact to the most minute detail, they are damn close and practicing with this method for many days has made it clear to me that while this method is time consuming, it is definitely a viable option for games without timedemo support.
The second graph is a bar graph that tells you the average framerate, the maximum framerate, and the minimum framerate. The minimum and average are important numbers here as we want the minimum to be high enough to not affect our gaming experience. While it will be the decision of each individual gamer what is the lowest they will allow, comparing the Min FPS to the line graph and seeing how often this minimum occurs, should give you a good idea of what your gaming experience will be like with this game, and that video card on that resolution.
Our tests are completely based around the second type of benchmark method mentioned above -- the manual run through.
System Setup and Benchmarks
Continuing on with our other recent GPU reviews, the Intel Core 2 Extreme X6800 is our processor of choice. We used the Intel 975XBX motherboard for our testing this time.
GeForce 8800 GTX SLI Test System Setup
Sound Blaster Audigy 2 Value
97.02 - NVIDIA
Windows XP Professional SP1
Call of Duty 2
HL2: Lost Coast
I tested these games at 1600x1200, 2048x1536 and 2560x1600, all running at 4xAA and 8xAF in-game settings.