Benchmark: Power, Temperature and Noise
| Dual-GPU Power Consumption Change |
CrossFire at idle | CrossFire at load | SLI at idle | SLI at load |
|---|---|---|---|---|
| 0% | 71.0% | 60.3% | 105% |
The EVGA GTX 580 SC and Sapphire HD 7950 OC might have been closely matched thus far, but there's a distinct gap in the power-draw department.
The Radeon is clearly more efficient, and the CrossFire numbers look good, don't they? One card turns off when idle, bringing system-wide power consumption down to a lovely 44 Watts, and a figure of 330 Watts while gaming is perfectly acceptable for a pair of high-end GPUs. The NVIDIA cards look thirsty in comparison.
| Dual-GPU Temperature Change |
CrossFire at idle | CrossFire at load | SLI at idle | SLI at load |
|---|---|---|---|---|
| 0% | 21.4% | 20.7% | 4.9% |
Lower power consumption tends to equals less heat, and thanks to the Dual-X cooler, Sapphire's Radeon HD 7950 OC is able to keep running at incredibly-cool temperatures.
Our tests found that AMD's reference design hit 69ºC under load, but a single Sapphire Radeon HD 7950 OC manages to shave off a further 13ºC - despite being pre-overclocked. A pair of Radeons do of course get warmer when gaming in CrossFire, but 68ºC is nothing short of admirable for a high-end, dual-card setup. The NVIDIA cards look toasty in comparison.
| Dual-GPU Noise Change |
CrossFire at idle | CrossFire at load | SLI at idle | SLI at load |
|---|---|---|---|---|
| 0% | 11.1% | 1.5% | 7.0% |
Lower power consumption tends to equals less heat, and less heat tends to equal less noise. The knock-on effect is clearly evident, as Sapphire's card is remarkably quiet in use.
Heck, a single EVGA GTX 580 SC when idle makes almost as much noise as a Sapphire HD 7950 OC working flat out. Rival partners have their work cut out in trying to develop a card that's as calm and collected as this.
The previous pages have shown that the GTX 580 still offers plenty of performance - and SLI works better than CrossFire in certain titles - but there's no argument over power consumption, temperature and noise. Sapphire's Radeon HD 7950 is comfortably better in all three areas.