AMD's Radeon HD 5000-Series: Measuring Power Efficiency

By Arnawa Widagda
published

Most of our graphics card reviews include power measurements at idle and load. But how do applications tax your GPU in between those two extremes? We line up a handful of different programs and monitor power use with a handful of AMD's latest cards.

Benchmark Results: Cinebench R11

We found this particular test to be very dependent on the CPU used. For instance, running both the Radeon HD 5670 and HD 5770 with an AMD Athlon II X2 250 drops the results from around 52-57 FPS to around 43-45 FPS.

Of the two mainstream cards, the Radeon HD 5770 takes the top spot, but the HD 5670 is not that far behind. A mere five frames per second separate the two, five frames away from a base of 60 FPS. If you look at the numbers, that additional frame rate costs about 25 W. Both Radeon HD 5870 cards are limited by the Phenom II X4 955 BE. V-sync was disabled, confirmed by observing more than 60 FPS in the benchmark at certain points.

The Radeon HD 5670 adds about 40 W, while the Radeon HD 5770 adds 70 watts to the base system’s power use. Both of these cards show just how much progress AMD has made since the 2900 XT. They offer significantly higher performance for significantly less power.

Since we were able to generate performance measurements with this test, we can calculate the performance per watt ratio.

Swipe to scroll horizontally
Header Cell - Column 0 Radeon 2900 XTRadeon HD 5670Radeon HD 5770Radeon HD 5870 1 GBRadeon HD 5870 2 GB
FPS32.2752.9957.6259.7359.27
Power (minus base system power consumption)1004370100121
FPS/watt0.321.230.960.590.48

As with Crysis, the Radeon HD 5670 offers better efficiency than the HD 5770. Both of the Radeon HD 5870s have to run full-speed in Photoshop CS4 and Cinebench R11, so they are handicapped in the power department compared to the Radeon HD 5670 and HD 5770.

Arnawa Widagda
30 Comments Comment from the forums
  • tony singh
    Very innovative article tom keep it up!! Similar article consisting of various cpus would be really useful.
    Reply
  • tacoslave
    gtx 480 and 460 for reference?
    Reply
  • Lutfij
    ^ nvidia would loose at this battle. period.
    Reply
  • spidey81
    I know the FPS/watt wouldn't be as good, but what if the 5670 was crossfired. Would it still be a better alternative, efficiency wise, than say a 5850?
    Reply
  • nforce4max
    Remember the R600 (2900xt) has a 80nm core while the 5870 has a 45nm core. Shrink the R600 and you will get the 3870 (55nm) that barely uses hardly any.
    Reply
  • rhino13
    And now just for fun we should compare to Fermi.

    Oh, wait, this just in:
    There is a Fermi comparison chart that was avalible but you needed to have two screens to display the bar graph for Fermi's power consumption and temperature. So the decission was made to provide readers with the single screen only version.
    Reply
  • aevm
    I loved this part:

    A mere 20 watts separate the Radeon HD 3300, HD 5670, HD 5770, and HD 5870 1 GB. So, in certain cases, the Radeon HD 5870 1 GB can still save enough power to close in on its more mainstream derivatives. Again, this is the case because the cards use a fixed-function video engine to assist in decoding acceleration, which is the same from one board to the next. Thus, even a high-end card behaves like a lower-end product in such a workload. This is very important, as you will see later on.

    My next PC will be used mostly for movie DVDs and Diablo 3. Apparently if I get a 5870 1GB I get the best of both worlds - speed in Diablo and low power consumption when playing movies.

    How about nVidia cards, would I get the same behavior with a GTX 480 for example?
    Reply
  • Onus
    For those not needing the absolute maximum eye candy at high resolutions in their games, the HD5670 looks like a very nice choice for a do-it-all card that won't break the budget.
    Next questions: First, where does the HD5750 fall in this? Second, if you do the same kinds of manual tweaking for power saving that you did in your Cool-n-Quiet analysis, how will that change the results? And finally, if you run a F@H client, what does that do to "idle" scores, when the GPU is actually quite busy processing a work unit?
    Reply
  • eodeo
    Very interesting article indeed.

    I'd love to see nvidia cards and beefier CPUs used as well. Normal non green hdds too. Just how big of a difference in speed/power do they make?

    Thank you for sharing.
    Reply
  • arnawa_widagda
    Hi guys,

    Thanks for reading the article.

    Next questions: First, where does the HD5750 fall in this? Second, if you do the same kinds of manual tweaking for power saving that you did in your Cool-n-Quiet analysis, how will that change the results? And finally, if you run a F@H client, what does that do to "idle" scores, when the GPU is actually quite busy processing a work unit?

    Have no 5750 sample yet, but they should relatively be close to 5770. For this article, we simply chose the best bin for each series (Redwood, Juniper and Cypress).

    The second question, what will happen when you tweak the chip? Glad you ask!! I can't say much yet, but you'll be surprised what the 5870 1 GB can do.

    As for NVIDIA cards, I'm hoping to have the chance to test GF100 and derivatives very soon.

    Take care.

    Reply