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

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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.

GPU Vs. CPU

Next, we installed all of our test cards on a platform powered by AMD’s  Athlon II X2 250. The objective was simple: using such a setup, does it make more sense to upgrade your processor (to an AMD Phenom II X4 955 BE) or a graphics card instead? We've limited testing to just two filters for this test (Chinese Painting and Kaleidoscope).

Offloading the filters and the encoding to the GPU really makes a difference. Accelerating the filters does offer some savings, but the most significant improvement comes from offloading the encoding task.

For those interested, you can see the differences in running these cards on the two tested platforms from the table below.

Swipe to scroll horizontally
Header Cell - Column 0 Athlon II X2 250 Chinese PaintingAthlon II X2 250 KaleidoscopePhenom II X4 955 BE Chinese PaintingPhenon II X4 955 BE Kaleidoscope
Radeon HD 5670313240298211
Radeon HD 5770283222265190
Radeon HD 5870 1 GB231205202167
Radeon HD 5870 2 GB233205203169

*seconds

So, is a new GPU a better choice than a quad-core processor for these sorts of apps? The difference between using the two processors with the Radeon HD 5670 and HD 5770 is about 15-18 seconds for the Chinese Painting filter and 30 seconds for the Kaleidoscope filter. Both Radeon HD 5870 cards show a difference of about 30-40 seconds. We would say that it’s worth investing in both upgrades. It would be interesting to see how a more affordable quad–core chip like the Athlon II X4 fares in this test.

These numbers represent total power consumed during the test. They paint a very positive argument for offloading tasks that are well-suited for the GPU. Below, you can see those results compared to those taken with the system equipped with the AMD Phenom II X4 955 BE.

Swipe to scroll horizontally
Header Cell - Column 0 Athlon II X2 250 Chinese PaintingAthlon II X2 250 KaleidoscopePhenom II X4 955 BE Chinese PaintingPhenom II X4 955 BE Kaleidoscope
Radeon HD 5670107129
Radeon HD 5770108129
Radeon HD 5870 1 GB98109
Radeon HD 5870 2 GB11101210

*Watt hours

Only 2 to 3 Wh separate these cards. Now, let’s look at the average power used for these two tests. We threw in the results for the AMD Phenom II X4 955 BE for comparison's sake.

Swipe to scroll horizontally
Header Cell - Column 0 Phenom II X4 955 BE Chinese PaintingPhenom II X4 955 BE KaleidoscopeAthlon II X2 250 Chinese PaintingAthlon II X2 250 KaleidoscopePhenom II X4 955 BE Chinese PaintingPhenom II X4 955 BE Kaleidoscope
Radeon HD 3300 (GPU not used)147133Row 0 - Cell 3 Row 0 - Cell 4 Row 0 - Cell 5 Row 0 - Cell 6
Radeon HD 5670Row 1 - Cell 1 Row 1 - Cell 2 111112147153
Radeon HD 5770Row 2 - Cell 1 Row 2 - Cell 2 125126168164
Radeon HD 5870 1 GBRow 3 - Cell 1 Row 3 - Cell 2 141139185185
Radeon HD 5870 2 GBRow 4 - Cell 1 Row 4 - Cell 2 169167210210

*Watts

Unless you have very tight restrictions on maximum power draw, the differences are not that great. If you're already considering or already using a quad-core processor, such as the AMD Phenom II X4 955 BE, using a GPU like the Radeon HD 5670 still roughly falls within the same power envelope. Though we can’t know for sure without generating the benchmark data, pairing an AMD Athlon II X4 with the Radeon HD 5670 seems to be a very good idea from the perspective of balance. Our experience with an AMD Athlon II X4 620 indicates that you could see savings around 20 W compared to the AMD Phenom II X4 955 BE. The Radeon HD 5770 and both Radeon HD 5870 cards are a different matter, though.

If you prefer to use a dual-core processor, you can employ the Radeon HD 5670, 5770, or even the Radeon HD 5870 1 GB and still remain within the same power draw as the system with an AMD Phenom II X4 955 BE and integrated graphics. The only exception here is the Radeon HD 5870 2 GB. System power draw with an Athlon II X2 250 and the Radeon HD 5870 2 GB is higher than a Phenom II X4 955 BE without a discrete graphics card.

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