Temperature & Acoustics / Power Consumption
Core Temperature & 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.
For the most part, the HD 6800 series’ temperatures stay well within check. However, their blower-style fans result in an acoustical profile that is slightly above that of the GTX 460. The noise both the HD 6870 and HD 6850 make won’t be noticed over the din of gaming or likely over your case fans since it can’t be classified as anything close to loud.
One disappointment was the XFX card here. Its temperatures were by far the best of the bunch due to the vapor chamber heatsink but it kicked up a racket when compared to the other cards. It is far from “loud” but it was noticeable when in-game sounds were turned down.
System 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.
Power consumption for the HD 6800 series is extremely good when you consider the framerates they are pumping out. The HD 6850 in particular was extremely frugal. We would recommend a good 450W PSU for the HD 6850 and a brand name 500W power supply for the HD 6870 depending on your system configuration.
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