Power Consumption

Cooling 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 variable scene with variable complexity just like any normal game.

The four result values are as following:

• Idle: Windows Vista 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.

Our testing confirms AMD's statement that the HD 5830 consumes more power than the HD 5850, even though almost a third of the chip is disabled. The higher power draw has several reasons. First of all, the clock speeds of the HD 5830 are higher than those of the HD 5850. I also noticed that the GPU voltage is +0.1V higher on our card than on a HD 5850 which is certainly to help with the clock binning of the ASICs. Last but not least, the HD 5850 reference design uses an expensive but efficient Volterra voltage regulator.

All these changes result in a fairly low performance per Watt result when comparing the HD 5830 to all other cards of the HD 5000 Series. However, compared to the rest of the market, the perf/Watt score is still excellent, leaving most NVIDIA cards behind by over 15%.