AMD Radeon R9 Nano 4 GB Review 95

AMD Radeon R9 Nano 4 GB Review

Fan Noise »

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, the values here 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 representing 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 7 Aero sitting at the desktop (1920x1080) with all windows closed and drivers installed. Card left to warm up in idle mode until power draw was stable.
  • Multi-monitor: Two monitors connected to the tested card, both using different display timings. Windows 7 Aero sitting at the desktop (1920x1080+1280x1024) with all windows closed and drivers installed. Card left to warm up in idle mode until power draw was stable. When using two identical monitors with 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 9 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, representing a typical gaming power draw. Average of all readings (12 per second) while the benchmark was rendering (no title/loading screen). In order to heat up the card, we run the benchmark once without measuring power consumption.
  • Peak: Metro: Last Light at 1920x1080, representing a typical gaming power draw. Highest single reading during the test.
  • Maximum: Furmark Stability Test at 1280x1024, 0xAA. This results in a very high no-game power-consumption that can typically be reached only 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.
With the Radeon R9 Nano, AMD uses a new approach to manage the card's power consumption. On the R9 Fury X, for example, the card is always running highest clock speeds, and only if the power limit is exceeded, will it throttle down. With the R9 Nano, the power limit is set so low the card is always throttling, effectively capping the board's power at a certain power draw target in this case 175 watts. Later in this review, we will analyze what effect the throttling has on in-game clock speeds.

In non-gaming states, we see a significant improvement over the Fury X because AMD's Fury has no watercooling pump that needs to be running at all times.

Single- and multi-monitor power consumption is now almost as good as with NVIDIA's latest offerings; especially the long overdue improvement in multi-monitor power draw is good to see.

Blu-ray playback is still horribly inefficient on AMD's latest cards, so you had better stick with NVIDIA in such a usage scenario.

Gaming power draw is the first test where we see the power limiter in action. Both tested cards are incredibly close together, which is to be expected because they are set to run at a specific power draw, not a specific clock frequency.

Furmark maximum power draw is low, lower than actual gaming power consumption, which suggests it is heavily throttled.

Next Page »Fan Noise