HD Decode Performance

The other aspect of PureVideo that matters is its decode acceleration. DVD decoding isn't really an issue these days, as even the slowest CPUs are powerful enough to handle DVD decoding - the new stress test is decoding of HD content. We used Windows Media Player 10 and the publicly available Terminator 2 trailers in 720p and 1080p formats. However because our test bed was limited to 1600 x 1200, the 1080p test was fairly useless as we were resolution bound on the machine, making the 720p test much more stressful.

We measured average, minimum and maximum CPU utilization over the entire 1:59 trailer. Our test bed was an Intel Pentium 4 570J (3.8GHz), however higher CPU utilizations on this test bed will translate into proportionally higher CPU utilizations on slower CPUs. We tested in both Overlay and VMR9 modes, the latter being directly applicable to Windows XP Media Center Edition as it uses VMR9 exclusively.

In Overlay mode in a window, ATI has significantly lower CPU utilization:

WMV9 CPU Utilization (Lower is Better) - Overlay Window - 720p Terminator Trailer
  Minimum Average Maximum
ATI 9.4 22 35.2
NVIDIA 14.8 28.3 40.6


WMV9 CPU Utilization (Lower is Better) - Overlay Full Screen - 720p Terminator Trailer
  Minimum Average Maximum
ATI 11.7 22.3 33.6
NVIDIA 25 37.7 46.9


ATI sees a very small performance penalty when scaling up to full screen, while NVIDIA faces a huge performance penalty in full screen mode. VMR9 is much more stressful on ATI than it is on NVIDIA, the winner here is NVIDIA.

WMV9 CPU Utilization (Lower is Better) - VMR9 Window - 720p Terminator Trailer
  Minimum Average Maximum
ATI 28.9 41.4 50.8
NVIDIA 15.6 26.6 40.6


WMV9 CPU Utilization (Lower is Better) - VMR9 Full Screen - 720p Terminator Trailer
  Minimum Average Maximum
ATI 31.3 42.2 50
NVIDIA 20.3 38.5 50.8


Even in full screen mode, NVIDIA is able to offer slightly lower CPU utilization than ATI.

DVD Playback Quality (continued 2) A Preview of the Future - Fully Hardware Accelerated HD Decode
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  • Cybercat - Monday, December 20, 2004 - link

    Oh, nevermind, that's for PCI Express 6800s, which are apparently the only cards that use the NV41 core. AGP 6800s use the NV40 core.
  • Novaoblivion - Monday, December 20, 2004 - link

    For anyone who wants it the link on Nvidia's site seems to working I just downloaded it.
  • Cybercat - Monday, December 20, 2004 - link

    http://nvidia.com/page/purevideo_support.html

    How does the 6800 have acceleration support if it's also based on the NV40 core?
  • skunkbuster - Monday, December 20, 2004 - link

    "At the same time, ATI sent us information on how to enable hardware acceleration of WMV9 on their cards before the forthcoming WMP10 update."


    would someone care to share this with the rest of us ?
  • KnightBreed - Monday, December 20, 2004 - link

    I hope nVidia plans to add support for decoding MPEG4-AVC HP at some point. Whether it's this product line or next, MPEG4 will be important for next generation optical media (whether it's HD-DVD or Blu-Ray).
  • LoneWolf15 - Monday, December 20, 2004 - link

    What makes me truly upset is that so far, the sites reviewing PureVideo has not take a stand for the consumers that own the 6800 and were promised the full PureVideo featureset by nVidia. Rather, sites are reviewing the tech, and ducking the issue, as if they are more concerned about continuing to receive nVidia products for review than they are for us. Who's looking out for the little guy?

    P.S. Anandtech's review states that the 6800 Standard has a fully functional video processor --this isn't fully true, as the AGP version according to nVidia's website, does not.
  • jamawass - Monday, December 20, 2004 - link

    Great review. Even though Nvidia doesn't always win the deinterlace test, it wins on picture quality in most tests.Looks like a 6600 Nvidia will be replacing my ATI as the next video card in my htpc.
  • Aquila76 - Monday, December 20, 2004 - link

    That is so retarded that it doesn't fully work on the 6800GT/Ultra. Why would they cripple their high end cards? I guess since they aren't very available it doesn't really matter. Hope they add the rest of the functionality to new revs of these cards.
  • GnomeCop - Monday, December 20, 2004 - link

    wow I guess they will get away with touting this feature on the AGP 6800Ultra/GTs , even though it doesn't fully work after all.
  • jg123 - Monday, December 20, 2004 - link

    I don't see a link on Nvidia's website for a trial mentioned in this article.

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