The Race is Over: 8-channel LPCM, TrueHD & DTS-HD MA Bitstreaming

It's now been over a year since I first explained the horrible state of Blu-ray audio on the PC. I'm not talking about music discs, but rather the audio component of any Blu-ray movie. It boils down to this: without an expensive sound card it's impossible to send compressed Dolby TrueHD or DTS-HD Master Audio streams from your HTPC to an AV receiver or pre-processor. Thankfully AMD, Intel and later NVIDIA gave us a stopgap solution that allowed HTPCs, when equipped with the right IGP/GPU, to decode those high-definition audio streams and send them uncompressed over HDMI. The feature is commonly known as 8-channel LPCM support and without it all high end HTPC users would be forced into spending another $150 - $250 on a sound card like the Auzentech HomeTheater HD I just recently reviewed.

For a while I'd heard that ATI was dropping 8-channel LPCM support from RV870 because of cost issues. Thankfully, those rumors turned out to be completely untrue. Not only does the Radeon HD 5870 support 8-channel LPCM output over HDMI like its predecessor, but it can now also bitstream Dolby TrueHD and DTS-HD MA. It is the first and only video card to be able to do this, but I expect others to follow over the next year.

The Radeon HD 5870 is first and foremost a card for gamers, so unless you're building a dual-purpose HTPC, this isn't the one you're going to want to use. If you can wait, the smaller derivatives of the RV870 core will also have bitstreaming support for TrueHD/DTS-HD MA. If you can't and have a deep enough HTPC case, the 5870 will work.

In addition to full bitstreaming support, the 5870 also features ATI's UVD2 (Universal Video Decoder). The engine allows for complete hardware offload of all H.264, MPEG-2 and VC1 decoding. There haven't been many changes to the UVD2 engine; you can still run all of the color adjusting post-processing effects and accelerate a maximum of two 1080p streams at the same time.

ATI claims that the GPU now supports Blu-ray playback/acceleration in Aero mode, but I found that in my testing the UI still defaulted to basic mode.

To take advantage of the 5870's bitstreaming support I had to use a pre-release version of Cyberlink's PowerDVD 9. The public version of the software should be out in another week or so. To enable TrueHD/DTS-HD MA bitstreaming you have to select the "Non-decoded high-definition audio to external device" option in the audio settings panel:

With that selected the player won't attempt to decode any audio but rather pass the encoded stream over HDMI to your receiver. In this case I had an Integra DTC-9.8 on the other end of the cable and my first test was Bolt, a DTS-HD MA title. Much to my amazement, it worked on the first try:

No HDPC errors, no strange player issues, nothing - it just worked.

Next up was Dolby TrueHD. I tried American History X first but the best I could get out of it was Dolby Digital. I swapped in Transformers and found the same. This ended up being an issue with the early PowerDVD 9 build, similar to issues with the version of the player needed for the Auzentech HomeTheater HD. Switching audio output modes a couple of times seemed to fix the problem, I now had both DTS-HD MA and Dolby TrueHD bitstreaming from the Radeon HD 5870 to my receiver.

One strange artifact during my testing was the 5870 apparently delivered 1080i output to my JVC RS2 projector. I'm not exactly sure what went wrong here as 1080p wasn't an issue on any other display I used. I ran out of time before I could figure out the cause of the problem but I expect it's an early compatibility issue.

I can't begin to express how relieving it is to finally have GPUs that implement a protected audio path capable of handling these overly encrypted audio streams. Within a year everything from high end GPUs to chipsets with integrated graphics will have this functionality.

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  • T2k - Thursday, September 24, 2009 - link

    quote:

    How would ET:QW be a good benchmark? Last I checked, it's still limited to the 30 FPS animations, which makes running it at more than 30 FPS pointless because everything will look jerky.
    I agree something like the CoD games should be included for comparison's sake, but they're hardly a good benchmark or taxing on a system. QW does not fall into the same category though, it has a smaller active playerbase than even L4D which lost a lot of players due to the lack of updates.


    Just whatF are you talking about, seriously? Is this some kind of new urban BS again?
    Look at other sites, they DID test it with ET:QW:
    http://www.techpowerup.com/reviews/ATI/Radeon_HD_5...">http://www.techpowerup.com/reviews/ATI/Radeon_HD_5...
    http://www.xbitlabs.com/articles/video/display/rad...">http://www.xbitlabs.com/articles/video/display/rad...

    and so on. BTW L4D is a passing fart in the wind while ET:QW is still going strong, stronger than UT3 (unfortunately because UT3 looks 10x better and the old ONS mode was awesome but Epic fucked it in UT3)

    Read other reviews before you post:
    http://forums.anandtech.com/messageview.aspx?catid...">http://forums.anandtech.com/messageview...amp;thre...
  • SiliconDoc - Wednesday, September 30, 2009 - link

    I see by your review links the 5870 just doesn't do well in ET:QW, everything else is closer to it and it gets beat worse, at 2560 high aa&af GTX295 slams it by 20%, so, of course, it was left out, in order to "pump up the percieved red number".
    -
    It's "not a good appearance".

    You'll just have to live with it for now like the rest of us.
  • number58 - Wednesday, September 23, 2009 - link

    Is this card any closer to saturating the pci-express 2.0 x16 slot? That was one of the big arguments in the P55 vs X58 debate. Would there be any loss of performance using these in crossfire on P55 compared to X58?
    Otherwise, great article. I think I'll be hanging on to my 4890 for a while though.
  • Kaleid - Wednesday, September 23, 2009 - link

    Look here for an answer:
    http://www.techpowerup.com/reviews/AMD/HD_5870_PCI...">http://www.techpowerup.com/reviews/AMD/HD_5870_PCI...
  • number58 - Wednesday, September 23, 2009 - link

    Thanks. That just about settles it. My next system will be Lynnfield based.
  • Zeratul - Wednesday, September 23, 2009 - link

    Please add support for Stereoscopic 3D, ATI. I'm not going back to play games in 2D, though I don't like nvidia's monopoly in that.
  • Arbie - Wednesday, September 23, 2009 - link

    Not just a review but an excellent technical discussion. It must have been a lot of work. Thanks for all of that, and do please follow up where you can on people's requests for more info on this very important card.

    Kudos to ATI/AMD for such an achievement. It looks like Nvidia is in big trouble.

    Arbie
  • SiliconDoc - Wednesday, September 23, 2009 - link

    rofl - Nvidia is in big trouble ? LOL
    Have you looked at the charts on wiki that predicted what this review shows ? Maybe you should take a gander at the Nvidia chart, now, and cry.
    --
    It is a nice review, although biased red here as usual.
    --
    I'd like to mention as he fretted about heat because of the 1/2 vent on the back of the card, I didn't notice overt despairing mention of the TWO rectangular exhaust ports on the fan end BLOWING HEAT INTO THE CASE.... which of course is deserved. Nice how that was held back as if overlooked. (Boy what trouble for Nvidia! hahha)
    Next we'll be told the red rooster tester put his hand next to the two internal exhaust ports, and "the air felt rather cool" so "rest assured not much heat is being pushed into your case", and "this doesn't matter".
    See, the trouble is already in the article, the trouble it took to spin it just so for Ati... lol... it's hilatrious!
  • ClownPuncher - Wednesday, September 23, 2009 - link

    Bizzarro SnakeOil, is that you?
  • SiliconDoc - Wednesday, September 23, 2009 - link

    No, this is me, the same me I've always been.
    Would you like to comment on the two internal exhaust ports of the 5870 that put sweltering heat into your case ?
    I guess you tried to ignore that entirely.
    You can always insult me again and avoid commenting on the heating exhaust ports ramping up your case temps on the 5870...
    That of course would be "the right thing to do".
    Perhaps call me crazy, and avoid the topic, right, you're good at that, huh.

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