Grudge Match: Triple Nvidia SLI vs. Triple ATI Crossfire
Six video cards, 1,000 watts, and two fried eggs later!
One powerful GPU is enough to render most games at ridiculous frame rates and insane resolutions. When you add two flagship GPUs to a system to make an SLI or Crossfire setup, it's the definition of excess. Triple SLI and Crossfire is (excuse us while we dip into our newspeak dictionary for a word) doubleplusexcess. Everything about three monster GPUs slapped into one system screams it. The frame rates are ridiculous, the power requirements are monumental, the heat is off the charts, and the cost--it falls under one of those "it's better not to ask" scenarios.
CyberPower sent over a system loaded to the hilt for us to check out in just such a configuration. The company had to build a machine capable of handling the immense loads that a triple GPU setup demands. Outside of heat, there were power, noise, and bottlenecking concerns. CyberPower used the sizeable Thermaltake Element V chassis, inside of which it installed one front-mounted 120mm fan for the drives, another in the back for the Asetek CPU water cooler, and a third wrapped around a ducting system that blows directly onto the video cards--an absolute necessity considering that one GeForce GTX 480 almost runs hot enough to boil water. On the side panel of the Thermaltake Element V sits a gigantic 230mm fan that blows directly onto the GPUs. An excellent cabling job keeps air flow unimpeded throughout the case. To make sure that the GPUs weren't bottlenecked by other hardware, CyberPower pushed the 3.33GHz flagship Intel Core i7 980X processor up to 4.2GHz and paired it with 6GB of 1600MHz Kingston HyperX DDR3 memory. On the storage side, there was a speedy 128GB Kingston SSD paired with a secondary 2TB drive for extra space. A massive 1,000-watt Corsair power supply feeds the rig with energy. Everything totals up to $4,500, which amounts to a princely sum but one heck of a machine.
Firing up the system for the first time, we were expecting something along the lines of a mild tornado or, at the very least, a vacuum cleaner. Surprisingly, the machine didn't emit more noise than your average computer when browsing the Web. In our air-conditioned offices, running the machine at full tilt didn't generate jet engine levels of noise, but it was enough to get our notice.
With the system configured the way it was--three side-to-side GPUs--we thought there would be more cause for alarm. In our earlier testing with the GeForce GTX 480, we pushed a single GPU well into the 90-degree Celsius range. Of course, we were also testing on an open-air test bed, which doesn't benefit from the well-routed air flow that a solid case design offers.
Despite all of the cooling efforts, we still saw high temperatures: 93 degrees. But that was with three GeForce GTX 480s in there and running for hours on end. We saw slightly lower temperature levels with three Radeon HD 5870s. Three power-hungry GPUs jammed into the space of a toaster are bound to cause trouble.
The machine can live in a well-cooled area, but we'd hesitate to recommend using it in a room with no air conditioning, and we definitely wouldn't recommend running it in the dead of summer. Of course, if you have nearly $5,000 to spend on a computer, it's likely you're not skimping on air conditioning. After multiple hours of testing on both setups, we would see the occasional graphical glitch or corrupted texture, which went away if we simply let the GPUs cool down a bit. The cooldown is relatively quick and probably took no longer than 10 to 20 seconds once all graphical load was gone.
Running two GPUs in a system is complicated, but adding a third and possibly a fourth doesn't help matters. In testing both setups, we encountered our fair share of anomalies; quirks that one might expect from being on the bleeding edge. But they certainly weren't something anyone would be thrilled about after spending more than $1,500 on the GPUs alone.
With triple Crossfire, we could not get Eyefinity working with all three cards enabled in Crossfire mode, leaving us to game on a single monitor. The moment we disabled triple Crossfire mode, we regained the ability to play on multiple monitors. We imagine ATI will address this in time. Until then, it's certainly not a great reason to grab three of these cards. We did get Eyefinity working with two GPUs, though.
On the Nvidia side, the company has yet to enable 3D Vision Surround, a feature that requires SLI. The company aims to enable this feature with the next release of its 256 driver, which should occur at the end of June. 3D Vision Surround enables multimonitor gaming, as well as 3D, which requires special monitors and Nvidia's 3D glasses.
One of these cards is quick, but two of them are even faster. Forced onto a single monitor, three powerful GPUs tied together can generate very high frame rates. But they do have their limitations when it comes to some games. The matchup is also not entirely fair because the GeForce 480 GTX costs $100 more per card than the Radeon HD 5870, and dropping in three dual-GPU Radeon HD 5970s wasn't an option.
Both triple card setups trounced their single and dual GPU brethren in all of the tests. We've got to hand it to Nvidia, though, because SLI scaling in general beat out Crossfire across the board in our tests. ATI's dual GPU Crossfire gave an averaged 1.6x gain over a single GPU, and when we jumped to three GPUs, we got an averaged 2.3x gain. With dual Nvidia GPUs, we got an averaged 2x gain, but three GPUs only moved us up to an averaged 2.5x. We're seeing some tremendous overall performance from both sets of cards, but we're far from a perfect 3x gain. Future driver revisions will likely improve performance.
In our tests, the jump from one GPU to two GPUs provided amazing gains. Nvidia seems to have the more mature multi-GPU solution from the games we tested, as two Nvidia GPUs pretty much doubled performance on all games. The jump to three GPUs also favors Nvidia, but the gains don't quite justify the hassle or cost. Temperatures also run quite high on both sets of video cards, and we can't recommend running them outside of a climate-controlled environment. Neither setup runs on multiple monitors at the moment, but the functionality should be present in time.Test System: Cyberpower - Intel Core i7 980x @ 4.2GHz, Kingston HyperX 1600MHz 6GB DDR3, Asus Rampage III Extreme Motherboard, Kingston 128GB SSD, Windows 7 64-bit Home Premium. Graphics cards: Nvidia GeForce 480 GTX, Forceware 257.15. ATI Radeon HD 5870, Catalyst 10.5.
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