|ASUS ENGTX580 GeForce GTX 580 Video Card|
|Reviews - Featured Reviews: Video Cards|
|Written by Olin Coles|
|Monday, 22 November 2010|
Page 18 of 19
VGA Power Consumption
For power consumption tests, Benchmark Reviews utilizes an 80-PLUS GOLD certified OCZ Z-Series Gold 850W PSU, model OCZZ850. This power supply unit has been tested to provide over 90% typical efficiency by Chroma System Solutions. To measure isolated video card power consumption, Benchmark Reviews uses the Kill-A-Watt EZ (model P4460) power meter made by P3 International.
A baseline measurement is taken without any video card installed on our test computer system, which is allowed to boot into Windows 7 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 before taking the idle reading. 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 (system without video card minus measured total) displayed in Watts for each specified test product:
* Results are accurate to within +/- 5W.
The factory overclocked ASUS GeForce GTX 580 video card surprised us with chilly idle and lukewarm loaded temperatures, and the surprises keep coming as we measure power consumption. The GeForce GTX 580 requires one eight-pin and one six-pin PCI-E power connection for proper operation. Resting at idle with no GPU load, the ASUS GeForce GTX 580 consumed a modest 31W by our measure. Compensating for a small margin of error, this falls roughly in-line with idle power draw from the GeForce 8800 GT and slightly less than the GeForce GTX 280 or GTX 465. Most notably, it's considerably lower than the GF100 inside the GeForce GTX 480... by nearly 26%.
Once 3D-applications begin to demand power from the GPU, electrical power consumption climbs. Because the GeForce GTX 580 uses a new hardware power monitoring technology not included on previous GeForce models, we've had to work around the power-throttling effects enabled with FurMark or OCCT. To do so, we merely renamed Furmark.exe to Crysis.exe and changed some file names and locations. Measured at full throttle with FurMark's 3D 'torture' load, the GeForce GTX 580 topped out at 245W maximum power draw. NVIDIA's stated max TDP is 244W, which is falls within our measurements - even once efficiency rating and margin of error are factored in.
Oddly enough, using ASUS Voltage Tweak to over-volt the ENGTX580 up to 925 MHz didn't exactly translate into higher power consumption. In fact, our average maximum readings were only 1-2 watts above the standard TDP. I realize that increasing from 962 mV to 1145 mV isn't a huge change, but I actually expected the power consumption to rise accordingly. While the idle power draw is identical to older models like the GeForce 8800 GT, it's better than the GeForce GTX 280 and more recent GTX 465 models. At full power load the GeForce GTX 580 matches up to the ATI Radeon HD 5870, but still operates well below the levels of a Radeon HD 5970.