For testing power consumption, we took our test system and plugged it
into a Kill-A-Watt power meter. For idle numbers, we allowed the system
to idle on the desktop for 15 minutes and took the reading. For load
numbers we measured the peak wattage used by the system while running
the OpenGL benchmark FurMark 1.9.2 at 640×480 resolution. We also ran the game HAWX 2 and looped the benchmark three times and recorded the highest Wattage seen on the meter.
Power Consumption Results: The AMD Radeon HD 7850 barely broke 253 Watts at load even with Furmark running and was able to idle at just 93 Watts (long idle with ZeroCore was 83 Watts). This card has a typical board power of ~130 Watts and is a good call for someone looking for an energy efficient card with just a single 6-pin video card power connector. The AMD Radeon HD 7870 GHz Edition was found to use 2 more Watts at idle and 34 Watts more at full load.
The AMD Radeon HD 7000 series has impressive board power numbers and you can see what AMD claims as the typical board power is in the table below.
|Maximum Board Power||Typical Board Power||Long Idle Power|
|Radeon HD 7970||250W||~230W||<3W|
|Radeon HD 7950||200W||~180W||<3W|
|Radeon HD 7870||–||~175W||<3W|
|Radeon HD 7850||–||~130W||<3W|
|Radeon HD 7770||100W||~80W||<3W|
|Radeon HD 7750||75W||~55W||<3W|
AMD has stopped using maximum board power ratings for video cards and is only giving typical board power ratings. AMD wouldn’t give us the maximum board power ratings even after asking for them, so based off the power connectors we know the Radeon HD 7850 won’t pull more than 150 Watts and the Radeon HD 7870 GHz edition tops out at 225 Watts. Based off the Radeon HD 7950 numbers we would guess that the Radeon HD 7870 tops out around 195 Watts.