|GIGABYTE Radeon HD 6850 GV-R685OC-1GD|
|Reviews - Featured Reviews: Video Cards|
|Written by Servando Silva|
|Wednesday, 19 January 2011|
Page 14 of 16
VGA Power Consumption
Life is not as affordable as it used to be, and items such as gasoline, natural gas, and electricity all top the list of resources which have exploded in price over the past few years. Add to this the limit of non-renewable resources compared to current demands, and you can see that the prices are only going to get worse. Planet Earth is needs our help, and needs it badly. With forests becoming barren of vegetation and snow-capped poles quickly turning brown, the technology industry has a new attitude towards turning "green". I'll spare you the powerful marketing hype that gets sent from various manufacturers every day, and get right to the point: your computer hasn't been doing much to help save energy... at least up until now. Take a look at the idle clock rates that AMD programmed into the BIOS for this GPU; no special power-saving software utilities are required.
The HD 6850 works at 100/300MHz in idle mode, while VDDC lowers to 0.950 volts. At full load it increases frequencies to 820/1050 and VDDC goes up to 1.15 volts. The good part is that the HD 6800 series can be overclocked while keeping idle frequencies, saving some energy and keeping lower temperatures. This wasn't possible with HD5800 without modified BIOS.
To measure isolated video card power consumption, I used the Kill-A-Watt EZ (model P4460) power meter made by P3 International. A baseline test is taken without a video card installed inside our computer system, which is allowed to boot into Windows and rest idle at the login screen before power consumption is recorded. Once the baseline reading has been taken, the graphics card is installed and the system is again booted into Windows and left idle at the login screen. Our final loaded power consumption reading is taken with the video card running a stress test using FurMark. Below is a chart with the isolated video card power consumption (not system total) displayed in Watts for each specified test product:
* Results are accurate to within +/- 5W.
The GIGABYTE GV-R685OC-1GD pulled just 29 (164-135) watts at idle and 148 (283-135) watts when running full out, using the test method outlined above. Consider PSU efficiency into the equations as I'm using an 80 plus bronze power supply. AMD has fixed the idle frequency problems that plagued the HD5xxx series, especially in CrossFireX mode. In idle mode, the BIOS needs to run the clocks WAY down, without any ill effects. We've become used to the low power ways of the newest processors, and there's no turning back.
I'll offer you some of final thoughts and conclusion on the next page...