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. It 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 1,920x1,080 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 1,920x1,080 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.