AMD Radeon HD 7970 GHz Edition review

AMD has made a big deal about this, its latest graphics card. At first, it’s hard to see why. This graphics card looks identical to the Radeon HD 7970 and has the same 2,048 stream processors and 3GB of GDDR5 memory running at 1.5GHz. The card still has one dual-link DVI port, an HDMI output and two mini DisplayPort outputs, needs one six-pin and one eight-pin PCI Express power connectors and is a reasonable 277mm long.

There are a couple of big differences, though. The new HD 7970 GHz Edition has an increased clock speed, up from 925MHz to 1GHz, and can boost dynamically up to 1.05GHz when the thermal envelope allows it. The card can also vary the GPU’s voltage to help it manage boost speeds more effectively.

This isn’t the first card we’ve seen which can dynamically boost its clock speed; the Nvidia GeForce GTX 680 can boost from 1.01GHz to 1.58GHz if there’s enough power and thermal capacity. However, we were surprised by how much of a difference the tweaks made to the AMD card’s performance.

We first tested the card with AMD’s current release driver, which at the time of writing was version 12.4. In our Dirt 3 test, which we run at 1,920×1,080 with 4x anti-aliasing and Ultra detail, the HD 7970 GHz Edition managed 104.3fps, up from 88fps with the standard HD 7970. In Crysis 2 at 1,920×1,080 and Ultra detail, the new 1GHz card managed 46.6fps, compared to 42.9fps from the original 925MHz HD 7970. These figures show the new card runs between 9% and 18% quicker than the old HD 7970 which, considering its clock speed is around 8% higher, is pretty impressive.

We also tested the card in Eyefinity mode with three monitors, for a total resolution of 5,760×1,080. In Dirt 3 at this resolution and with 4x anti-aliasing and Ultra detail, the HD 7970 GHz Edition managed 45.9fps, compared to 41.5fps for the plan HD 7970 – a 10% speed increase.

These results are impressive enough on their own, but AMD had another trick up its sleeve. The beta Catalyst 12.7 drivers promise significant performance gains across all AMD’s graphics cards, and this was certainly the case with the HD 7970 GHz Edition. With Catalyst 12.7 installed, the standard 925MHz HD 7970 jumped up to 100fps in Dirt 3 at 1,920×1,080, while the HD 7970 GHz Edition managed a huge 113fps. In Crysis 2, the new drivers saw the normal HD 7970 increase its frame rate to 44.3fps, while the GHz Edition managed a smooth 48.7fps.

With the new drivers, Dirt 3 in Eyefinity mode saw increases to 46.2fps and 50.6fps for the HD 7970 and HD 7970 GHz Edition. The new, faster HD 7970, coupled with the new drivers, makes the HD 7970 finally a match for the Nvidia GeForce GTX 680, with almost identical frame rates in all our game tests. There was one problem; although we found the beta drivers to be stable during all our game tests, we saw some strange results in Crysis 2 when running in Eyefinity mode at 5,760×1,080. In one test, the benchmark ran at a smooth 35.4fps, which is a huge increase over the 21fps we saw from the HD 7970. However, running the test again after a reboot saw the frame rate drop down to 15fps. We also saw no more than 15fps from the normal HD 7970 using the beta 12.7 drivers. We’ll have to wait for the next driver release to see how well the new card can cope with Crysis 2 on three monitors.

The Radeon HD 7970 GHz Edition is a card with better performance than its specifications would suggest, showing that the fairly modest clock speed increase and dynamic overclocking produce some serious benefits. Problems with Crysis 2 in Eyefinity mode aside, the combination of this card and AMD’s latest beta drivers is enough to challenge Nvidia’s GeForce GTX 680 for the high-end graphics card crown. The Radeon HD 7970 GHz Edition is also set to be a similar price to the standard HD 7970, at about £350. This makes it about £70 cheaper than the GTX 680, and a far more sensible choice than the absurdly priced and absurdly powerful Nvidia GeForce GTX 690. It may not be the faster card you can buy, then, but its still our new Ultimate graphics card.