AMD Radeon HD 6990 review

Let’s get this out of the way immediately: the AMD Radeon HD 6990 is the fastest graphics card money can buy. It’s also one of the hottest and loudest cards we’ve ever seen, but if you’ve looked at the price and are genuinely considering a purchase such trivialities won’t concern you. For the rest of us this article will be a purely aspirational dreamland.

As with the last generation’s Radeon HD 5970, this monstrous card slaps two top-end graphics cores onto one long slab of PCB. The two chips, codenamed Antilles, are tweaked versions of the HD 6970’s Cayman XT core. The 880MHz clock has been reduced to 830MHz as standard across both cores, and the 2GB of GDDR5 memory per core (for a total of 4GB) has been slowed from 1,375MHz to 1,250MHz to keep things manageable.

Each core has 1,536 stream processors for a total of 3,072 across the whole card – interestingly enough, that’s 128 less than the HD 5970 – and the HD 6990’s 5.2 billion transistors tops every other graphics card on the market. It’s one serious piece of enthusiast gaming hardware.

We’ll start with the lesser of our gaming benchmarks, if only to prove that they’re rendered largely redundant. In Just Cause 2, an average of 96fps in our 1,920 x 1,080 Very High benchmark, with 8x anti-aliasing, is far beyond the 74fps of Nvidia’s top-end GTX 580. In Stalker: Call of Pripyat, the HD 6990 averaged of 81fps in our maximum quality 1,920 x 1,080 benchmark, comprehensively trouncing the GTX 580’s 49fps.

But it’s Crysis that pushes a card the most, so let’s get to the important figures. First, the HD 6990 achieved an average of 67fps in our Very High quality, 1,920 x 1,080 test, versus 54fps from the GTX 580 and 64fps from the Radeon HD 5970, AMD’s own previous dual-GPU flagship.

That’s not a huge leap over the last generation, so we’ll ramp up the settings: at 2,560 x 1,600 – the resolution of choice for 30in TFTs – with Very High quality settings, the GTX 580 met its match, yet the HD 6990 managed a massive 53fps (see graph).

Enabling 8x anti-aliasing on top of that makes for a very tough test, but seemingly not tough enough: the HD 6990 breezed through with a staggering 44fps.