Now that we know it's possible to achieve very similar performance by taking AMD's Tahiti GPU and its GDDR5 memory as far as they'll go, it's equally important to evaluate power use, thermals, and acoustics.
The blue bar represents idle power usage, and the green bar shows load consumption at each card's stock frequencies. There’s a 23 W spread between the contenders under load, likely reflecting a number of factors, including cooling solutions and voltage settings.
The dark grey bar is indicative of power consumption under load of the overclocked configurations. The only real surprise is a relatively high result from Sapphire's board.
Despite an eclectic range of cooling solutions, measured temperatures are quite similar at idle and under load using factory-supplied frequencies. The exception is VisionTek's card, perhaps as a result of its reference heat sink and fan. The rest of the field’s overclocked thermal results mirror the power draw chart.
Noise is a critical consideration when comparing graphics cards with the same GPU, particularly when we consider that AMD's reference implementation was observed to be quite noisy under load back when the card launched.
A majority of today's contenders perform much more admirably, regardless of whether the card is resting idle or working hard under a load. Of course, VisionTek’s board struggles as a result of its reliance on that familiar cooler from AMD. Overclocked and under load, both the Gigabyte and VisionTek cards generate more noise than we'd like, even as the rest of the pack is significantly quieter.
MSI’s Twin Frozr IV performs exceptionally well in this situation, generating slightly more noise than idle under load, and just a tad more than that overclocked.
- AMD's Radeon HD 7970: More Affordable, More Available
- Gigabyte GV-R797OC-3GD
- HIS 7970 IceQ X2 Turbo And Turbo X
- MSI R7970 Lightning
- Sapphire HD 7970 OC
- VisionTek Radeon HD 7970
- Test System Setup And Benchmarks
- Benchmark Results: 3DMark 11 And Crysis 2
- Benchmark Results: AvP And Metro 2033
- Overclocking AMD's Radeon HD 7970
- Power, Temperature, And Noise
- Five Radeon HD 7970s; One Rises To The Top