GeekTech: nVidia's Powerful, Complicated Quad SLI

Marc SimonIt's too expensive. It's too complicated. And it's likely to run basic apps--the ones most of us use every day--a bit slower than a single-card system. So why would you buy a desktop with nVidia's new, high-end Quad SLI technology?

Because you wanna play Oblivion at superhigh resolutions and settings on a massive 30-inch display, that's why. And because (of course) you have entirely too much money.

The thing is, just spending a ton of money on a Quad SLI system may not get you what you want. There's nothing wrong with the technology; but if your PC vendor doesn't implement it correctly, you're stuck with an expensive desktop that has more bark than bite.

When nVidia launched Quad SLI, it said the technology was for people who wanted an "Extreme HD" gaming experience. The technology uses a pair of giant graphics cards, each containing two ultra-high-end 7900 GTX graphics chips. The result is something like a video-processing supercomputer that can crank out impressive frame rates at high resolutions, such as 1920 by 1200 and 2560 by 1600, while using extreme antialiasing settings (to smooth jagged edges) and steep anisotropic filtering settings (to help render crisper textures).

In fact, if you don't have a big monitor capable of running those resolutions--such as Dell's 24-inch or 30-inch monsters--or the cash to buy one, don't bother with Quad SLI. The folks at nVidia will tell you that--just ask them.

Another thing they'll tell you is that Quad SLI is indeed a complicated technology, which is why you can't currently buy dual-chip cards to use in building your own system. A Quad SLI PC requires several particular components--like a power supply powerful enough to run the sun--and some specific motherboard and BIOS tweaks.

The companies selling these high-end systems are supposed to know all of these things; but unfortunately, the one that sent us our system apparently did not.

The Quad SLI system we tested came from Aeoncraft. Our shipping $4495 Aeon-8000 Quad came stuffed with high-end components, including an AMD Athlon FX-60 processor, 2GB of Corsair memory, two 150GB Western Digital Raptor 10,000 RPM hard drives, and--of course--the two gigantic graphics cards.

Despite that impressive array of hardware, the system didn't perform on a par with its pedigree in our initial tests.

In WorldBench 5 tests, the PC earned a score of 119. That's not slow, but it's well below the mark of 142 posted by our current top performer, Xi Computer's MTower 64 AGI-SLI (which has the same CPU and same amount of memory as the Aeon-8000 Quad, but uses a single, older GeForce 7800 GTX graphics board).

Equally surprising was the Aeon's performance on our admittedly basic desktop graphics tests: It managed a frame rate of 372 frames per second on Unreal Tournament 2003 at 1280 by 1024 resolution, compared to the Xi's frame rate of 438 fps. The two systems' scores on Return to Castle Wolfenstein were nearly identical, however. (As noted, nVidia suggests running Quad SLI at a resolution of 1680 by 1050 or higher, but our basic tests max out at 1280 by 1024.)

Because of the overhead of running four GPUs, we expected the Quad SLI to run a tad slower than a comparably equipped system with a single card. And let's face it, nobody is buying a system like this to type Microsoft Word documents and surf the Web. Still, the performance results we recorded were clearly out of whack. To see whether the Quad SLI was responsible for the system's mediocre overall numbers, we removed one of the dual-GPU boards, disabled one of the two GPUs on the remaining board, and reran our tests. The system's WorldBench 5 score rocketed to 136.

We shared our testing information with Aeoncraft and (more specifically) nVidia, to help us figure out what was going on. It turned out that our high-end system needed some fine-tuning.

After much back-and-forth with nVidia, we determined that Aeoncraft had shipped us a PC with the wrong BIOS, some incorrect settings, and a slightly dated video driver. The driver part is forgivable--these things rev all the time--but the BIOS issues suggest sloppy craftsmanship, especially on a system this pricey.

After installing the proper BIOS, we reran our basic WorldBench 5 tests, and the system scored a much more reasonable 134--not tops, but pretty good. The system did a lot better on our basic desktop graphics tests, too.

Of course, where a system like this should really shine is with games. To test this sucker at the resolutions nVidia recommends, we had to reconfigure a couple of our standard graphics tests. But even at high resolutions, the system posted mixed results at typical antialiasing and anisotropic filtering settings.

For example, in our FarCry test (with antialiasing at 4X and anisotropic filtering at 8X), the Quad setup registered 85 fps at 1920 by 1200 resolution and 48 fps at 2560 by 1600 resolution, whereas a Dual SLI setup (with two standard 7900 GTX boards) posted 94 fps and 59 fps, respectively. A single 7900 GTX board hit speeds of 65 fps and 33 fps on the same tests.

Our Doom 3 tests showed similar numbers for both the Quad and Dual SLI systems at the same settings: the Quad SLI posted 105 fps and 51 fps, the Dual SLI hit 103 fps and 56 fps, and the single card notched 65 fps and 30 fps.

Not until we moved out of the game setting and cranked up the SLI-only antialiasing and anisotropic filtering settings did the Quad SLI finally show some world-class muscle.

In our Doom 3 test running at 1920 by 1200 resolution with SLI settings at 8X antialiasing and 16X anisotropic filtering, the Quad SLI system posted 86 fps versus 64 fps for the Dual SLI system. And at 2560 by 1600 resolution, the Quad hit 48 fps while the Dual posted 29 fps.

In our Far Cry test using the same settings, the Quad SLI achieved 84 fps versus 49 fps for the Dual SLI at 1920 by 1200 resolution, and it rolled out 46 fps against 28 fps for the Dual SLI at 2560 by 1600 resolution.

Does anyone need to run a game at such high antialiasing and anisotropic filtering settings? I don't think so. In fact while I believe that these technologies contribute to better-looking game play, I'm unconvinced that such super-high settings enhance what the average person perceives on screen. But do some people want to run them that high anyway? Sure they do.

In the end, Quad SLI does offer performance benefits when you use the right combination of resolution and settings. But I wouldn't recommend it unless you're fanatical about gaming, you have enough money to buy a giant monitor, and you've convinced yourself that you can see the difference between 4X and 8X antialiasing (by the way, Quad SLI actually offers up to 32X antialiasing).

What about Aeoncraft and their setup snafu? The company gets credit for coming clean about its mistakes, and a rep assures me that Aeoncraft is shipping new systems with the right settings and is working with existing Quad SLI owners to get their rigs up to speed. Still, I find it disheartening that any PC vendor would offer such an expensive product without knowing how to make it work the way it's supposed to. Maybe that's why I'm so big on building my own PCs: I know who to blame if something doesn't work right.

Tom Mainelli hasn't stopped drooling over that obnoxiously large 30-inch Dell monitor since it arrived. You can e-mail him at .