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GPU Vs. CPU

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


Athlon II X2 250 Chinese PaintingAthlon II X2 250 KaleidoscopePhenom II X4 955 BE Chinese PaintingPhenon II X4 955 BE Kaleidoscope
Radeon HD 5670313
240
298
211
Radeon HD 5770283
222
265
190
Radeon HD 5870 1 GB231
205
202
167
Radeon HD 5870 2 GB233
205
203
169

*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.


Athlon II X2 250 Chinese PaintingAthlon II X2 250 KaleidoscopePhenom II X4 955 BE Chinese PaintingPhenom II X4 955 BE Kaleidoscope
Radeon HD 567010
7
12
9
Radeon HD 577010
8
12
9
Radeon HD 5870 1 GB9
8
10
9
Radeon HD 5870 2 GB11
10
12
10

*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.


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)147
133




Radeon HD 5670

111
112
147
153
Radeon HD 5770

125
126
168
164
Radeon HD 5870 1 GB

141
139
185185
Radeon HD 5870 2 GB

169
167
210210

*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.

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Top Comments
  • 18 Hide
    Lutfij , August 24, 2010 9:23 AM
    ^ nvidia would loose at this battle. period.
  • 14 Hide
    tony singh , August 24, 2010 6:32 AM
    Very innovative article tom keep it up!! Similar article consisting of various cpus would be really useful.
Other Comments
  • 14 Hide
    tony singh , August 24, 2010 6:32 AM
    Very innovative article tom keep it up!! Similar article consisting of various cpus would be really useful.
  • 3 Hide
    tacoslave , August 24, 2010 6:59 AM
    gtx 480 and 460 for reference?
  • 18 Hide
    Lutfij , August 24, 2010 9:23 AM
    ^ nvidia would loose at this battle. period.
  • 3 Hide
    spidey81 , August 24, 2010 11:20 AM
    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?
  • 0 Hide
    nforce4max , August 24, 2010 11:50 AM
    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.
  • 7 Hide
    rhino13 , August 24, 2010 12:34 PM
    And now just for fun we should compare to Fermi.

    Oh, wait, this just in:
    Quote:
    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.
  • 0 Hide
    aevm , August 24, 2010 12:51 PM
    I loved this part:

    Quote:
    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?
  • -2 Hide
    Onus , August 24, 2010 12:57 PM
    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?
  • 0 Hide
    eodeo , August 24, 2010 1:34 PM
    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.
  • 3 Hide
    arnawa_widagda , August 24, 2010 3:42 PM
    Hi guys,

    Thanks for reading the article.

    Quote:
    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.

  • 0 Hide
    JohnnyLucky , August 24, 2010 4:03 PM
    Thanks for including mainstream applications.

    Interesting comments about Furmark.

  • 0 Hide
    xbsoft , August 24, 2010 6:24 PM
    >> TEST SYSTEM: AMD Phenom II X4 955 Black Edition (3.2 GHz, >>>>>> 8
  • -2 Hide
    mattmock , August 24, 2010 6:30 PM
    Quote:
    It just means you typically will never encounter such an extreme usage scenario.

    I have to disagree, there are several ways a user can fully load their graphics card in normal use. I have found that my GPU utilization and fan speed go to %100 when I play the dice mini-game in The Witcher. The game only has to render a small game board and the frame rate goes into the 200-300 range. Some thing similar occurs when I hit the pause key in stalker.
  • 0 Hide
    Fokissed , August 24, 2010 11:03 PM
    xbsoft(3.2 GHz, >>>>>> 8

    bad penis joke?
  • 1 Hide
    MartenKL , August 24, 2010 11:13 PM
    FPS/watt uses average FPS during the test but max wattage? I am very disappointed by this flawed logic from toms hardware. Spending an entire page describing why everyone else uses flawed testing for benchmarking power efficiency and then doing this simple error is just embarrassing.
  • 1 Hide
    MartenKL , August 24, 2010 11:30 PM
    I forgot to say I am very interested in this kind of benchmarks and I am glad Toms Hardware is writing a big piece on it, sorry for the harsh words. For me total Wh per completed task for the entire system is the most interesting number. To me that is the only way to measure efficiency. add to that idle power draw and every user can calculate their own usage (by adding tasks and idle hours). Sorry and thanks yet again for an article with a very important topic. My interest is noise and mechanical wear rather than power cost and environment.
  • 0 Hide
    tubers , August 25, 2010 2:50 AM
    Fermi comparison please :) 
  • 0 Hide
    mayne92 , August 25, 2010 2:45 PM
    What a great article by Tom's (Arnawa)! Probably one of the best articles I have read in a long time! Enjoyed the article because was very detailed and you explained everything so well and I LOVE my tech reviews! A Fermi comparison would have been nice but I know that you said that you don't have them to play with so it's said as a request. Hats off to you Arnawa...for a great read...
  • 0 Hide
    eddieroolz , August 25, 2010 11:07 PM
    Really paints in perspective the power of GPUs compared to CPUs. I really wish that one day we'll be able to use the GPU for central processing.
  • 0 Hide
    EDIGX2 , August 26, 2010 6:00 PM
    Hello everyone
    Well i think this article inspired form the movie that AMD has release lately.
    That movie called as i think "Mis understanding"here's the link: http://www.youtube.com/watch?v=2QkyfGJgcwQ
    As we all know AMD is innovative in power consumption as well It's Graphics I read such this review in Anandtech.com ...Just WOW....Loads Of Noise and power flowed for Fermi VGAs . In this review we see the smooth performance for 5670 and 5770.
    and another thing that we should give a hint on is You know releasing Fermi after six month of releasing 5000 series...I think it's good in performance but not after 6 Months!!! but awful in power consuming and noise and heat!!
    Take care guys
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