Size, Noise and HeatThe Radeon HD 6950 and 6970 are slightly shorter than the Radeon HD 5870. They measure 27.5 cm instead of 28 cm. The cooler is lined and there's a metal heatsink plate on the top of the card.
There has been negative progress on noise levels in comparison with the previous generation. At idle, the fan runs at 30% of its maximum speed, compared with 25% for the 5800 series. The noise generated is therefore quite noticeable (43.3 dB(A)) and may be suite annoying for some. The GeForce GTX 570 and GTX 580 do better here, at a little over 40 dB(A). Don't forget that 3 dB(A) is equivalent to doubling the intensity of the sound.
During 3D gaming, the results are mitigated. It generates less noise (55.5 dB(A)) than the Radeon HD 5870, however, it's still a good deal louder than the GeForce GTX 570 (49.7 dB(A)). Heat levels are absolutely fine at 44°C in 2D and 91° during gaming.
Power ConsumptionFormerly a strong point in the Radeon HD 5000 series, power consumption levels have actually gone up slightly with the Radeon HD 6900s, with an average increase of 10 watts both in idle and 3D activity. Our test computer used 100 watts in 2D and 396 watts in 3D. These readings are almost comparable to those obtained with the GeForce GTX 570, though the GTX 570 uses slightly more power.
Gaming PerformanceNVIDIA has done a really thorough job with the GeForce 500 series and has increased gaming speeds by around 20% on the previous generation. We were waiting to see how AMD could respond and we have to say we are quite disappointed.
In order to deliver improved performance levels, AMD has increased the clocks on its graphics chip (880 MHz against 850 MHz) and doubled the amount of memory, now up to 2 GB (clocked at 1375 MHz against 1200 MHz).
AMD has also implemented a new feature known as 'PowerTune'. Somewhat comparable to the 'turbo' feature on previous generations of card, this technique allows you to push the clocks of the graphics chip beyond its original clock speed (+20% max), so long as the 3D load doesn't already take it over the maximum threshold for the thermal design power (TDP).
Click on the image to see all our readings
and compare this model with other graphics cards
In practice, we didn't get a particularly satisfying result. In some cases, we noted a gain of around 1% and in others no gain at all, implying that our test games all took the card to its maximum TDP. So, while we like the idea, in practice it doesn't appear to have been implemented particularly effectively.
Performance levels themselves are pretty good, as you can run all current games at high resolution with texture filters activated.
This places the HD 6970 well below the NVIDIA GTX 570 (around 7% faster) and on a par with the GeForce GTX 480. AMD will have to price it quite aggressively to keep users interested in this card which is as noisy as the GTX 570 (see above).
The new high-end AMD graphics card is something of a disappointment. Although not at all bad in absolute terms, the small gain in power doesn't make up for the fact that its cooling system is louder than the competitor's model. The release of the GeForce GTX 570 was apparently not anticipated by AMD and the company will now have to price its high-end card quite aggressively if it wants to bank a decent number of sales.
Graphics Cards: Performance Index Tables