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. In this particular test, all power consumption results were verified with a second power meter for accuracy.

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 graphics test #1 on 3DMark11. 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:

In the previous section we discovered how well the new and improved NVIDIA cooling solution managed temperatures for a pair of Fermi GF110 GPUs on the GeForce GTX 590 video card. In terms of power consumption, the results were generally similar in scale. Keeping in mind that Gemini houses two independent high-performance graphics processors, it's expected that the graphics card will require significant power even despite the use of a 10-phase advanced digital power controller. The GeForce GTX 590 accepts two 8-pin PCI-E power connections for proper operation, and will not display a picture on the screen unless proper power has been supplied. NVIDIA recommends a 700W power supply unit for stable operation, which should include the two required 8-pin PCI-E connections without using any adapters. The power consumption statistics discussed below are absolute maximum values, and may not represent real-world power consumption created by the average video game:

Resting at idle with no GPU load, the GeForce GTX 590 consumed a 53W - or roughly 26W per GPU by our measure. Compensating for a small margin of error, this level of power consumption is only 7W more than the opposing Radeon HD 6990 requires at idle. This also roughly matches idle power draw from the older ATI Radeon HD 5970 video card, while being lower than many of the older-generation single-GPU solutions. Once 3D-applications begin to demand power from the twin Fermi GPUs, electrical power consumption really climbs. Measured at full throttle using 3dMark11 benchmark suite (GT1), the GeForce GTX 590 topped out at 396W maximum power draw, which is 31W higher than NVIDIA's stated max TDP of 365W. Our measurements represent absolute maximum limits, since most real-world applications and video game do not demand 100% GPU load.

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