AMD Radeon HD 7770 & 7750 Launch Review - PAGE 17

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.

From a thermal standpoint both of the Cape Verde graphics cards were solid. They both displayed excellent thermal results and were extremely quiet across the board. The only time we noticed much fan noise at all was when we manually set the HD 7770 fan speed above 50% so that we could comfortably increase the voltage level.

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.

Both the HD 7750 and HD 7770 really delivered when it came to performance-per-watt. At the default settings, the idle and load power rating was a sparse 99W and 161W for the HD 7750. As for the HD 7770 it managed to run at a low 106W during idle and 212W under full load. So, what both cards lack in overall performance they make up for in sheer power efficiency. However, after we over-voltage the HD 7770 the power consumption increased substantially.