Sapphire Radeon HD 5970 2GB OC Edition Review

Heat & Acoustics

For all temperature testing, the cards were placed on an open test bench with a single 120mm 1200RPM fan placed ~8” away from the heatsink. The ambient temperature was kept at a constant 22°C (+/- 0.5°C). If the ambient temperatures rose above 23°C at any time throughout the test, all benchmarking was stopped. For this test we use the 3DMark Batch Size test at it highest triangle count with 4xAA and 16xAF enabled and looped it for one hour to determine the peak load temperature as measured by GPU-Z.

For Idle tests, we let the system idle at the Vista desktop for 15 minutes and recorded the peak temperature.


ATI made a big deal about binning cores for efficiency and it seems this worked quite well for them considering the temperatures we saw throughout testing. Indeed, these are some of the lowest temperatures we have seen when testing a dual GPU card.

Amazingly enough, these low temperatures weren’t the result of extremely high fan speeds since the HD 5970 never made much noise. Its fan did spin up from time to time and made itself noticeable but its acoustical footprint pales in comparison to what we experienced with the HD 4870 X2.

Power Consumption

For this test we hooked up our power supply to a UPM power meter that will log the power consumption of the whole system twice every second. In order to stress the GPU as much as possible we once again use the Batch Render test in 3DMark06 and let it run for 30 minutes to determine the peak power consumption while letting the card sit at a stable Windows desktop for 30 minutes to determine the peak idle power consumption. We have also included several other tests as well.

Please note that after extensive testing, we have found that simply plugging in a power meter to a wall outlet or UPS will NOT give you accurate power consumption numbers due to slight changes in the input voltage. Thus we use a Tripp-Lite 1800W line conditioner between the 120V outlet and the power meter.


The efficiency and performance per watt of the ATI’s latest cards has never been in question and the HD 5970 does nothing but reinforce that point. Even though its idle power consumption is slightly higher than a pair of HD 5850 1GB cards, the real eye-opener is how much power it needs when under load. It really is amazing to see a card that can almost compete on a level footing with two HD 5850 cards consume about 20W less.