Indeed, the 6950 and 6970 boards are the first in ATI’s new line. A dual-GPU version will be released later this year, under the Antilles name.
The new design, seen here in the HIS ATI Radeon HD 6950, implements a narrower Stream Processor Unit (VLIW4) that allows more room for an increased number of SIMD engines (these are designed to simultaneously execute multiple computing instructions - the more of these, the more efficiently and quickly the card can render graphics). The 6950 has 22 of the latter (the 6970 has 24), as opposed to a mere 14 in the case of the 6870. Even the mighty 5870 had just 20 SIMD engines.
See also: AMD Radeon HD 6970 review
The new architecture sees the 6950 and 6970 making do with fewer stream processors. Whereas the Radeon 5870 boasted 1600 of these, the new high-end 6970 offers 1536, whilst the HIS ATI Radeon HD 6950 makes do with 1408.
But it’s worth remembering that the sheer number of stream processors isn’t crucial – the high-calibre nVidia GeForce GTX 580 has just 512, for example. The new stream processors in the Cayman are also said to be more versatile and efficient than in older cards.
Ample compensation comes with the significantly larger number of Texture Units – the HIS ATI Radeon HD 6950 has 88 of these, eight more than the 5870, and 24 more than on the GTX 580. In short, AMD’s new narrower, more efficient and more versatile design looks exactly the ticket for 2011.
Other specifications are pretty impressive too. The HIS ATI Radeon HD 6950 may be the cheaper of the Caymans, but it still comes with 2GB of GDDR5 – nVidia’s 580 comes with a mere 1536MB as standard – while the core-clock speed of 800MHz is a good starting figurem.
The memory clock goes up to 1250MHz (in effect a massive 5000MHz when the quadrupling of GDDR5 memory is taken into account), and the HIS ATI Radeon HD 6950’s memory bandwidth of 160GBps is comfortably superior to the 152GBps of the GTX 580, not to mention the 134.4GBps notched up by the Sapphire Radeon HD 6870.
The HIS ATI Radeon HD 6950 needs two 6-pin connectors for power. This card isn’t light on power demands though. It’s not incredibly noisy, but that TDP of 225W is high – 6W more than the GTX 570, if short of the 250W of the extortionate GTX 480.
Given the interesting new hardware, the high memory bandwidth and a generally impressive set of specifications (including the high complement of memory), you might expect the HIS ATI Radeon HD 6950 to offer something pretty special in games testing.
In truth, it doesn’t. The HIS ATI Radeon HD 6950 is several frames ahead of the GTX 470, while costing £15-£30 more.
In HAWX, the HIS ATI Radeon HD 6950’s figures of 164 and 128 frames per second (at 1680x1050 and 1920x1200) place it 13 and 8 fps ahead of the GTX 470, and 9 and 7 fps ahead of the 5870.
In BattleForge, the lower general scores see the gap close to 7.5fps and 9.1fps over the GTX 470, and 4fps and 5ps over the 5870.
The gap is closer still in Heaven, with the 6950 7-3.2fps faster than the GTX 470, and 2.9-1.2fps faster than the 5870. Similar results were seen in Crysis.
Perhaps the more interesting battle is with the 6870. The HIS ATI Radeon HD 6950 is faster in every test, but is it fast enough to justify a price difference of £40-£60? In BattleForge, it’s 13-14.7fps faster than the 6870, and 7.3-3.4fps faster in Heaven. In HAWX, the lead is a more impressive 18-17fps, but is even this enough to justify the price difference?
NEXT: our expert verdict >>