DirectX 11 CrossFire on a stick
The recipe: Take two of the fastest GPUs on the planet capable of running DirectX 11, specially chosen for their low voltage leakage. Toss in two gigabytes of high-speed GDDR5 memory. Mix all ingredients into a card with high-end Japanese solid capacitors and a souped-up thermal dissipation system. The result: the XFX Radeon HD 5970—a GPU so yummy, you may even go back for seconds.
While the product name doesn’t hint at the card’s dual-GPU nature, there’s no mistaking the presence of two graphics chips when you check out the back of the board. Then there’s the sheer size of it: At more than 12 inches, you’ll need a high-end PC case that’s deep enough to handle this monster. You’ll need a beefy power supply, too, since the HD 5970 burns 294W at full throttle—and that’s if you don’t overclock it. The good news is the card consumes just 42W at idle, less than double the idle power of a single HD 5870, thanks to an enhanced deep-sleep mode for the slave GPU.
The XFX Radeon HD 5970: two 5870 GPUs, two gigabytes of GDDR5, a card that's more than a foot long.
AMD built in a number of enhancements over its previous dual-GPU effort, the 4870 X2. The card now sports a full-length vapor chamber mounted on the back of the board, which enables the card to support up to 400W of heat dissipation—enough headroom for some serious overclocking. A simplistic overvolting tool is available on AMD’s website, allowing you to tweak the voltage setting a little higher in order to push clock speeds—albeit at the expense of additional power consumption.
The HD 5970 does make a few compromises in order to shoehorn 4 billion transistors worth of GPUs onto one card. Core and memory clocks are lower than on the single-GPU Radeon HD 5870, at 725MHz and 1,000MHz, respectively (versus the HD 5870’s 850MHz and 1,200MHz). AMD has built in lots of overhead, so if you have good case cooling and a suitable PSU, you can push the clock speed much higher if you want. One other compromise is the use of a mini-DisplayPort connector. This kept all three display connectors on one expansion slot cover, so that a full-height exhaust could be added to the second slot cover.
OK, so the card is physically large and burns nearly 300W at full throttle. But does it perform? Yes, Virginia, this card does indeed deliver the goods. It’s the fastest single graphics card we’ve ever tested. At $600, this card had better be fast. XFX’s limited lifetime warranty, complete with the ability to transfer said warranty when you resell the card, eases that financial pain a bit.
What you get for your six C-bills is an incredibly speedy graphics card that delivers tremendous gaming performance and doesn’t eat kilowatts when idle. So if what you want is the fastest graphics card you can buy, then the XFX Radeon HD 5970 is the card for you. Just make sure your case can handle it.