AMD Radeon HD 6970 review

Graphics card manufacturers usually release the high-end versions of a new architecture first, and then scale down the design to provide more affordable versions of the card. AMD, having now discarded the ATI brand, has taken a different strategy with its 6000-series.

We saw the mid-range 6800 cards a couple of months back, such as the Radeon HD 6870, and now we have the more enthusiast-orientated 6900 pairing – consisting of the HD 6970 and 6950 predictably. Both are actually based on a different architecture from their little siblings.

The cards’ Cayman graphics core has the same 40nm fabrication process as the Barts core in 6800 cards, and the whole 5000 series. It’s not the major step forward then that we’d hoped for, but it’s still an impressive chip, the biggest AMD have ever made, with 2,640 million transistors, up from 2,154 from the previous generation.

There are still plenty of interesting revisions in the design. Dual graphics engines are one innovation, so it can handle greater quantities of geometry and has two tessellation engines – DirectX 11 supports tessellation to add more detail into scenes. AMD claim they have increased tessellation performance by up to three times over their previous architecture.

The HD 6970 has a massive 1,536 stream processors, which support new image quality features. The key one of these is Enhanced Quality Anti-Aliasing (EQAA), which takes extra samples from a scene during anti-aliasing for almost no performance hit. The extra samples increase accuracy and so improve edge smoothing, it’s only really noticeable at low resolutions and low anti-aliasing settings – which aren’t why you buy a high-end card like this.