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.

Eyefinity Lower Idle Power & Better Overcurrent Protection
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  • poohbear - Wednesday, September 23, 2009 - link

    is it just me or is anyone else disappointed? next gen cards used to double the performance of previous gen cards, this card beats em by a measly 30-40%. *sigh* times change i guess.
  • AznBoi36 - Wednesday, September 23, 2009 - link

    It's just you.

    The next generations never doubled in performance. Rather they offered a bump in framerates (15-40%) along with better texture filtering, AA, AF etc...

    I'd rather my games look AMAZING at 60fps rather than crappy graphics at 100fps.
  • SiliconDoc - Monday, September 28, 2009 - link

    Golly, another red rooster lie, they just NEVER stop.
    Let's take it right from this site, so your whining about it being nv zone or fudzilla or whatever shows ati is a failure in the very terms claimed is not your next, dishonest move.
    ---
    NVIDIA w/ GT200 spanks their prior generation by 60.96% !

    That's nearly 61% average increase at HIGHEST RESOLUTION and HIGHEST AA AF settings, and it right here @ AT - LOL -

    - and they matched the clock settings JUST TO BE OVERTLY UNFAIR ! ROFLMAO AND NVIDIA'S NEXT GEN LEAP STILL BEAT THE CRAP OUT OF THIS LOUSY ati 5870 EPIC FAIL !
    http://www.anandtech.com/video/showdoc.aspx?i=3334...">http://www.anandtech.com/video/showdoc.aspx?i=3334...
    --
    roflmao - that 426.70/7 = 60.96 % INCREASE FROM THE LAST GEN AT THE SAME SPEEDS, MATCHED FOR MAKING CERTAIN IT WOULD BE AS LOW AS POSSIBLE ! ROFLMAO NICE TRY BUT NVIDIA KICKED BUTT !
    ---
    Sorry, the "usual" is not 15-30% - lol
    ---
    NVIDIA's last usual was !!!!!!!!!!!! 60.69% INCREASE AT HIGHEST SETTINGS !
    -
    Now, once again, please, no lying.
  • piroroadkill - Wednesday, September 23, 2009 - link

    No, it's definitely just you
  • Griswold - Wednesday, September 23, 2009 - link

    Its just you. Go buy a clue.
  • ET - Wednesday, September 23, 2009 - link

    Should probably be removed...

    Nice article. The 5870 doesn't really impress. It's the price of two 4890 cards, so for rendering power that's probably the way to go. I'll be looking forward to the 5850 reviews.
  • Zingam - Wednesday, September 23, 2009 - link

    Good but as seen it doesn't play Crysis once again... :D

    We shall wait for 8Gb RAM DDR 7, 16 nm Graphics card to play this damned game!

  • BoFox - Wednesday, September 23, 2009 - link

    Great article!

    Re: Shader Aliasing nowhere to be found in DX9 games--
    Shader aliasing is present all over the Unreal3 engine games (UT3, Bioshock, Batman, R6:Vegas, Mass Effect, etc..). I can imagine where SSAA would be extremely useful in those games.

    Also, I cannot help but wonder if SSAA would work in games that use deferred shading instead of allowing MSAA to work (examples: Dead Space, STALKER, Wanted, Bionic Commando, etc..), if ATI would implement brute-force SSAA support in the drivers for those games in particular.

    I am amazed at the perfectly circular AF method, but would have liked to see 32x AF in addition. With 32x AF, we'd probably be seeing more of a difference. If we're awed by seeing 16x AA or 24x CFAA, then why not 32x AF also (given that the increase from 8 to 16x AF only costs like 1% performance hit)?

    Why did ATI make the card so long? It's even longer than a GTX 295 or a 4870X2. I am completely baffled at this. It only has 8 memory chips, uses a 256-bit bus, unlike a more complex 512-bit bus and 16 chips found on a much, much shorter HD2900XT. There seems to be so much space wasted on the end of the PCB. Perhaps some of the vendors will develop non-reference PCB's that are a couple inches shorter real soon. It could be that ATI rushed out the design (hence the extremely long PCB draft design), or that ATI deliberately did this to allow 3rd-party vendors to make far more attractive designs that will keep us interested in the 5870 right around the time of GT300 release.

    Regarding the memory bandwidth bottleneck, I completely agree with you that it certainly seems to be a severe bottleneck (although not too severe that it only performs 33% better than a HD4890). A 5870 has exactly 2x the specifications of a 4890, yet it generally performs slower than a 4870X2, let alone dual-4890 in Xfire. A 4870 is slower than a 4890 to begin with, and is dependent on Crossfire.

    Overall, ATI is correct in saying that a 5870 is generally 60% faster than a 4870 in current games, but theoretically, a 5870 should be exactly 100% faster than a 4890. Only if ATI could have used 512-bit memory bandwidth with GDDR5 chips (even if it requires the use of a 1024-bit ringbus) would the total memory bandwidth be doubled. The performance would have been at least as good as two 4890's in crossfire, and also at least as good as a GTX295.

    I am guessing that ATI wants to roll out the 5870X2 as soon as possible and realized that doing it with a 512-bit bus would take up too much time/resources/cost, etc.. and that it's better to just beat NV to the punch a few months in advance. Perhaps ATI will do a 5970 card with 512-bit memory a few months after a 5870X2 is released, to give GT300 cards a run for its money? Perhaps it is to "pacify" Nvidia's strategy with its upcoming next-gen that carry great promises with a completely revamped architecture and 512 shaders, so that NV does not see the need to make its GT300 exceed the 5870 by far too much? Then ATI would be able to counter right afterwards without having to resort to making a much bigger chip?

    Speculation.. speculation...
  • Lakku - Wednesday, September 23, 2009 - link

    Read some of the other 5780 articles that cover SSAA image quality. It actually makes most modern games look worse, but that is through no fault of ATi, just the nature of the SS method that literally AA's everything, and in the process, can/does blur textures.
  • strikeback03 - Wednesday, September 23, 2009 - link

    I don't know much about video games, but in photography it is known that reducing the size of an image reduces the appearance of sharpness as well, so final sharpening should be done at the output size.

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