Sapphire Radeon HD 7850 OC Review - PAGE 14

Temperature:

To measure core GPU temperatures, we run three in-game benchmarks and record the idle and load temperature according to the min and max temperature readings recorded by MSI Afterburner. The games we test are Crysis 2, Lost Planet 2 and Metro 2033. We run these benchmarks for 15 minutes each. This way we can give the included thermal solution and GPU time to reach equilibrium.

The thermal solution used on the Sapphire HD 7850 OC performed flawlessly, not necessarily for the outright thermal performance (in that regard it tied with the reference design) but because it was able to so while remaining quieter than the reference design. The fans were able to efficiently dissipate the heat at much lower RPM than those on the reference cards.

Power Consumption:

To measure power usage, a Kill A Watt P4400 power meter was used. Note that the numbers represent the power drain for the entire benchmarking system, not just the video cards themselves. For the 'idle' readings we measured the power drain from the desktop, with no applications running; for the 'load' situation, we took the sustained peak power drain readings after running the system through the same in-game benchmarks we used for the temperature testing. This way we are recording real-world power usage, as opposed to pushing a product to it's thermal threshold.

The HD 7850 excels when it comes to performance-per-watt, though Sapphire's overclocked edition consumes slightly more power than the reference model. To be sure, the overclocked frequencies increased the power consumption by only 6% so the additional performance won't come at the cost of a higher electric bill.