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Heavier Lifting

ATI Stream: Finally, CUDA Has Competition
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One scenario we haven’t seen yet is transcoding into 1080 high-definition. I originally ran several tests that involved interpolating from a lower resolution to a higher one. Some people might be tempted to do this because, after all, your Blu-ray player does it for DVDs, and the results look better, right? The difference is that Blu-ray players and other upscalers apply a lot of filtering in order to make interpolated images look more natural. When you tell an encoder to make more pixels out of fewer pixels, it simply magnifies the pixels, leaving you with jagged, nasty looking results and a much larger file to boot. Why bother?

AMD argued with me that no one would bother trying to perform this sort of upscaling, and I suspect they’re right. I sure wouldn’t. Of course, AMD had good cause to persuade me. My test results showed CUDA with a clear advantage on such operations. Still, I threw the tests out. AMD’s logic was sound, and it’s probably worth reprinting part of their email to me here:

The objectives of real-life transcoding are:

  • Reducing the file size on the hard drive while trying to keep the best quality possible. This can be achieved by:
  •     Reducing the resolution of the video, e.g. going from 1080p to 720p or SD
  •     Or adding compression while keeping the same resolution like HD to HD, e.g. converting MPEG-2 HD to H.264 HD
  • Converting for a portable device
  • Transcoding from HD, SD to these portable devices to file the player requirements
  • Converting to social media like YouTube
  • Transcoding from HD, SD to these site requirements
  • Authoring DVDs or Blu-ray Discs (BD)
  • For DVDs, that means converting to MPEG-2 SD from HD or SD
  • For BD, that means converting to MPEG-2 HD, H.264 HD or VC-1

This is almost a complete list. The one significant omission is captured in our final test for similar resolution transcoding. I took the 115 MB Terminator 2 WMV HD trailer, which displays at 1440x1080 with black bars, and transcoded it into Espresso’s MPEG-4 1920x1080 profile. As H.264 emerges as the de facto choice for high-def media, a lot of people are going to want to migrate over the HD files they have in other formats.

Neither GPU technology accelerates WMV decoding, both accelerate MPEG-4 encoding, and we have very similar CPU-only output times, so it should be a fair fight. Both sides score remarkable gains with GPU assistance, and this bout testifies to just how much time savings GPU computing might offer to transcoders when multiplied across sizable batch jobs. But CUDA takes the clear lead here, knocking over two minutes off of Stream’s already impressive encode time. Had we been working with an MPEG-2 HD file here rather than WMV HD, I suspect Stream would have eked out a win, so keep that in mind as you consider your own transcoding needs.

Final score: AMD 3, Nvidia 4. However, I’m going to call this a tie, and MPEG-2 decoding may be the deal-maker depending on your usage scenarios. If you need it and all we’re talking about is performance, then Stream wins. If you don’t need MPEG-2 acceleration and you want more GPGPU-enabled applications to choose from, then CUDA is likely your sensible choice today.

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Top Comments
  • 12 Hide
    Spanky Deluxe , June 15, 2009 11:21 AM
    Stream and CUDA are likely to go the way of the dodo soon though. OpenCL's where its at. Unfortunately its a tad hard to get programming with it right now since you need to be a registered developer on nVidia's Early Access Program or you have to be a registered developer with Apple's developer program with access to pre-release copies of Snow Leopard.
    Virtually no one will bother using CUDA or Steam after OpenCL's out - why limit yourself to one hardware base after all? It'd be like writing Windows software that only ran on AMD processors and not Intel. Developers will not bother writing for both when they can just use one language that can run on both hardware platforms.
Other Comments
  • 0 Hide
    radiowars , June 15, 2009 6:11 AM
    So..... TBH they both work pretty well, I hope that we don't start a whole competition over this.
  • -7 Hide
    falchard , June 15, 2009 6:16 AM
    Did someone necro an old topic? I think ATI has been talking about ATI Stream for a while. I know atleast a year since FireStream.
  • 0 Hide
    cl_spdhax1 , June 15, 2009 6:46 AM
    arcsoft simhd plugin is currently only enabled for n- cuda graphic cards.
  • 2 Hide
    Andraxxus , June 15, 2009 7:34 AM
    They're good but hopefully they will manage to improve them more. Competition is good for business.
  • -7 Hide
    DjEaZy , June 15, 2009 8:38 AM
    ... why just now talk about? I use it sins Catalyst 8.12...
  • 0 Hide
    IzzyCraft , June 15, 2009 8:43 AM
    Stream is old but not nearly as old and compatible as CUDA I'd get it a year or two more when more capable cards circulate the market and trickle down to the people before i would call it competition.

    Well it's good to see more then just 1 app that supports it.
  • 7 Hide
    ThisIsMe , June 15, 2009 9:11 AM
    Just for the sake of it, and the fact that many pros would like to know the result, it would be nice to see comparisons like this using nVidia's Quadro cards vs. ATI's FirePro cards.
  • -4 Hide
    ohim , June 15, 2009 9:25 AM
    why use 185.85 since those drivers are a total wreck

    http://forums.nvidia.com/index.php?showtopic=96665&st=0&start=0

    13 pages with ppl having different problems with that driver
  • 0 Hide
    Anonymous , June 15, 2009 11:09 AM
    I think the second graph on the "Mixed Messages" page isn't the right graph.

    It's the same graph from the following "Heavier Lifting" page instead of a graph for the 298MB VOB file that should be shown?
  • 12 Hide
    Spanky Deluxe , June 15, 2009 11:21 AM
    Stream and CUDA are likely to go the way of the dodo soon though. OpenCL's where its at. Unfortunately its a tad hard to get programming with it right now since you need to be a registered developer on nVidia's Early Access Program or you have to be a registered developer with Apple's developer program with access to pre-release copies of Snow Leopard.
    Virtually no one will bother using CUDA or Steam after OpenCL's out - why limit yourself to one hardware base after all? It'd be like writing Windows software that only ran on AMD processors and not Intel. Developers will not bother writing for both when they can just use one language that can run on both hardware platforms.
  • -2 Hide
    wasteoftime , June 15, 2009 11:28 AM
    How come Folding is not something you guys ever cover in your CUDA comparisons. The main reason I left an ati card and bought an nvidia was the huge increase in my ppd.
  • 5 Hide
    armistitiu , June 15, 2009 11:52 AM
    wasteoftimeHow come Folding is not something you guys ever cover in your CUDA comparisons. The main reason I left an ati card and bought an nvidia was the huge increase in my ppd.

    Yeah...that's just what i want from a GPU : Folding@Home. I find video transcoding to be a more 'useful' way of using you GPU.
    Nice article. Haven't seen one in a long time.
  • -2 Hide
    thejerk , June 15, 2009 12:52 PM
    why did i feel the expresso "overview" page was an embedded advertisement?

  • 0 Hide
    sailer , June 15, 2009 12:54 PM
    wasteoftimeHow come Folding is not something you guys ever cover in your CUDA comparisons. The main reason I left an ati card and bought an nvidia was the huge increase in my ppd.


    I agree. The last three cards that I bought were Nvidia cards, based solely on their folding performance. When gaming, I prefer an ATI card. Oh yeah, I have four computers, three using Nvidia cards for folding and one with an ATI card for gaming. I think it would be great if the reviews included Folding@Home performance. It might also encourage ATI to make cards that did better for folding.
  • 0 Hide
    astrotrain1000 , June 15, 2009 12:58 PM
    Anandtech was saying that the output quality from ATI wasn't very good, but I didn't see any mention of it here. Can anyone confirm or deny, I have a 4870 but I'd like to know how the output quality is before I buy Expresso.
  • 0 Hide
    nickcardwell , June 15, 2009 12:59 PM
    I have used newer cards from both Nvidia and ATI, I also love my Mac. I would really like to see OpenCL take off. It's cross platform with Nvidia and ATI on both Mac and PC. That to me would end the CUDA / Stream war and bring it back to simply who builds the better GPU.
  • 0 Hide
    thejerk , June 15, 2009 1:01 PM
    "Final score: AMD 3, Nvidia 4. However, I’m going to call this a tie..."

    It actually IS a tie. You awarded NVidia a point for not offering an option for WMV encoding,
    even though performance showed a very slight, but measurable, increase with Stream enabled.

    You didn't give credit where credit was due. Do it right the next time.
  • 0 Hide
    lire210 , June 15, 2009 1:28 PM
    the gpu looks a bit weak on the ati side. when was the gtx 280 ever ment to go head to head with a hd4870. i would like to suggest a hd4890 for da job bit more even. that is if we are going on who drivers are better which seems to be more of the focus considering the lack of hardware evenness.
  • -1 Hide
    JPForums , June 15, 2009 1:57 PM
    There is no mention of how good the output quality is. How does it compare to the source? How does it compare to nVidia?
  • 3 Hide
    williamvw , June 15, 2009 4:37 PM
    Hey, all. Many thanks for the initial feedback. A few notes:

    1. I would have loved to test with the Folding@home app. I actually tried to when doing the former CUDA-on-a-budget article. However, I quickly discovered that the results were meaningless because the work loads varied too much. NVIDIA helped solve this problem by creating a series of batch files for SETI@home that used a common work load, and that's what you see in the article. However, there is no such tool that I know of for Folding@home and AMD/ATI has not released an equivalent set of testing tools for SETI@home.

    2. I count seven charts -- 4 to 3. I did give the better coding point to NVIDIA on page 7. NVIDIA has 0 points on page 6 and two points by the end of page 7. :-)

    3. The side-by-side captures you see in the later article pages show samples of Stream vs. CUDA output. These are taken from GPU-accelerated output files. To my eye, they look almost identical, but I offer them up for you to make your own judgments. I would say that the output quality issues that plagued Stream's initial launch have been remedied.

    4. Yes, I agree that, ultimately, OpenCL and DirectX 11 will lay the entire Stream/CUDA issue to rest. But that's someday. For now, this article's purpose was to take a look at today's technology.

    5. I tested with an HD 4890, not a 4870. Apologies if there are any typos to the contrary.

    6. There is no behind-the-scenes money changing hands that resulted in my page detailing CyberLink Espresso. I developed that page for two reasons. First, as I mentioned, Espresso is the ONLY application today with even support for both Stream and CUDA, so it made sense to me that many people might want to buy it because of its agnostic support -- and it's a great tool. Second, in part because of this agnosticism, CyberLink has been immensely helpful to me in writing this article in a fair, even-minded, and accurate manner. The company helped me through many nights, often maintaining email dialogues well past midnight. So forgive me for being enthusiastic about the product. If CyberLink's customer support is even half its press support, I think you'll be pleased.
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