Power ConsumptionCooling modern video cards is becoming more and more difficult, especially when users are asking for quiet cooling solutions. That's why the engineers are now paying much more attention to power consumption of new video card designs.
For this test we measure power consumption of only the graphics card, via PCI-Express power connector(s) and PCI-Express bus slot. A Keithley Integra 2700 with 6.5 digits is used for all measurements. Again, the values here reflect card only power consumption measured at DC VGA card inputs, not the whole system.
We chose 3DMark03 Nature as a standard test representing typical 3D usage because it offers: - very high power draw - high repeatability - is a standard benchmark that is supported by all cards - drivers are actively tested and optimized for it - supports all multi-GPU configurations - easy to obtain - fairly compact in size - test runs a constant duration and renders a non-static scene with variable complexity just like any normal game.
The four result values are as following:
- Idle: Windows 7 Aero sitting at the desktop (1280x1024 32-bit) all windows closed, drivers installed. Card left to warm up in idle until power draw is stable.
- Average: 3DMark03 Nature at 1280x1024, 6xAA, 16xAF. This results in the highest power consumption. Average of all readings (12 per second) while the test was rendering (no title screen).
- Peak: 3DMark03 Nature at 1280x1024, 6xAA, 16xAF. Highest single reading during the test.
- Maximum: Furmark Stability Test at 1280x1024, 0xAA. This results in a very high non-game power consumption that can typically be reached only with stress testing applications. Card left running stress test until power draw converged to a stable value.
- Blu-ray Playback: Power DVD 9 Ultra is used at a resolution of 1920x1200 to play back the Batman: The Dark Knight disc with GPU acceleration turned on. Playback starts around timecode 1:19 which has the highest data rates on the BD with up to 40 Mb/s. Playback left running until power draw converged to a stable value.
In terms of power consumption NVIDIA's new GTX 590 can not compete with AMD's HD 6990, the only exception being Blu-ray power where AMD's recent cards are notoriously bad because they don't reduce memory clock in that state.
Overall the high power consumption limits NVIDIA in what they can do with their two GTX 580 GPUs. The constraining parameter for a dual GPU design like this is heat, which is equivalent to power draw. So, with a higher performance per Watt, NVIDIA could have offered a faster card fitting the 375 W power envelope set forth by the 2x 8-pin PCI-E configuration.
Due to NVIDIA's power limiting system being active in our "Furmark Maximum Test", and no way to disable that feature, this data single point should not be considered the maximum possible power consumption as the normal 3D Maximum test show higher power draw than 334 W.