AMD Radeon HD 6790 review

The AMD Radeon HD 6870 and AMD Radeon HD 6850, released late last year, both gained Best Buy awards, but we were still left waiting for the follow-up to the cheaper HD 5770 – our favourite card of the previous generation.

This has now arrived, in the shape of the HD 6790. According to AMD, this slots in between the HD 5770 and the HD 6850 in AMD’s range and, at £116 for the Sapphire version of the card (below), its pricing is right between the £100 HD 5770 and the £140 HD 6850.

The new card’s specification isn’t spectacular. It has 800 stream processors, which is the same number of units as the HD 5770 but 160 fewer than the HD 6850. 1GB of GDDR5 RAM comes fitted, just like on the HD 6850, and this runs at 1.05GHz – 150MHz slower than the HD 5770’s RAM. The HD 6790’s 256-bit memory bus does eliminate the HD 5770’s 128-bit bottleneck, though. The card’s core clock speed is 840MHz – similar to the HD 5770’s 850MHz.

The ‘mid-range’ HD 6790 can draw 150W, and has two PCI-E power connectors.

We were surprised by the HD 6790’s design, as it looks like a much more powerful card – it’s 262mm long, which is longer than the HD 6850 and huge for a mid-range card, plus it has two six-pin power connectors. Luckily, the HD 6790’s performance in our benchmarks came close to matching its looks. In Crysis at 1,680×1,050 with High detail and 4x anti-aliasing enabled, the card gave us a smooth 41.8fps – a big improvement on the HD 5770’s 33.6fps, and not far off the HD 6850’s 48.7fps. Pushing the resolution up to 1,920×1,080 narrowed the gap, with the HD 6790 managing 37.2fps compared to the more expensive HD 6850’s 42.6fps.