Power Consumption
Cooling modern video cards is becoming more and more difficult, especially with users asking for a quiet cooling solution, which is why engineers are now paying much more attention to the power consumption of new graphics card designs. An optimized fan-profile is also one of the few things board vendors can create to impress with reference designs where they are prohibited from making changes to the thermal solution or components on the card.
For this test, we measure the power consumption of only the graphics card via the PCI-Express power connector(s) and PCI-Express bus slot. A Keithley Integra 2700 digital multimeter with 6.5-digit resolution is used for all measurements. Again, these values only reflect the card's power consumption as measured at its DC inputs, not that of the whole system.
We use Metro: Last Light as a standard test for typical 3D gaming usage because it offers the following: very high power draw; high repeatability; is a current game that is supported on all cards; drivers are actively tested and optimized for it; supports all multi-GPU configurations; test runs in a relatively short time and renders a non-static scene with variable complexity.
Our results are based on the following tests:
- Idle: Windows 10 sitting at the desktop (1920x1080) with all windows closed and drivers installed. The card is left to warm up in idle mode until power draw is stable.
- Multi-monitor: Two monitors are connected to the tested card, and both use different display timings. Windows 10 is sitting at the desktop (1920x1080+1280x1024) with all windows closed and drivers installed. The card is left to warm up in idle mode until power draw is stable. When using two identical monitors with the same timings and resolution, power consumption will be lower. Our test represents the usage model of many productivity users who have one big screen and a small monitor on the side.
- Blu-ray Playback: Power DVD 15 Ultra is used at a resolution of 1920x1080 to play back the Batman: The Dark Knight Blu-ray disc with GPU acceleration turned on. Measurements start around timecode 1:19, which has the highest data rates on the BD with up to 40 Mb/s. Playback keeps running until power draw converges to a stable value.
- Average: Metro: Last Light at 1920x1080 because it is representative of a typical gaming power draw. The average of all readings (12 per second) while the benchmark was rendering (no title/loading screen) is used. In order to heat up the card, the benchmark is run once without measuring power consumption.
- Peak: Metro: We use Last Light at 1920x1080 as it produces power draw typical to gaming. The highest single reading during the test is used.
- Maximum: We use Furmark Stability Test at 1280x1024, 0xAA. This results in a very high no-game power-consumption reading that can typically only be reached with stress-testing applications. We report the highest single reading after a short startup period. Initial bursts during startup are not included as they are too short to be relevant.
Power consumption results of other cards on this page are measurements of the respective reference design.
Just like other members of the Maxwell GPU family, the GTX 980 Ti impresses with its awesome power consumption.
In non-gaming states, the card uses slightly more power than reference, which is as expected due to the pump's power consumption, but the overall difference is really small, much smaller than I expected.
During gaming, the card requires a bit more power than the reference design, which is as expected because of its higher clocks, but the resulting performance is increased as well, and by much more than it usually would be for how much power draw has gone up. Thanks to watercooling and low temperatures, efficiency is improved a lot because any silicon chip will draw more power the hotter it is (at the same clock). Overall, this makes the Gigabyte GTX 980 Ti WaterForce the most power efficient graphics card we have ever tested.
Furmark maximum power reaches around 300 W, which seems to be the card's stock power limit as defined by Gigabyte. Given the card has two 8-pin power connectors, I had hoped for a slightly higher limit, which would have provided additional potential for Boost to clock the card higher out of the box.