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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  • Ryan Smith - Wednesday, September 23, 2009 - link

    We do have Cyberlink's software, but as it uses different code paths, the results are near-useless for a hardware review. Any differences could be the result of hardware differences, or it could be that one of the code paths is better optimized. We would never be able to tell.

    Our focus will always be on benchmarking the same software on all hardware products. This is why we bent over backwards to get something that can use DirectCompute, as it's a standard API that removes code paths/optimizations from the equation (in this case we didn't do much better since it was a NVIDIA tech demo, but it's still an improvement).
  • DukeN - Wednesday, September 23, 2009 - link

    I have one of these and I know it outperforms the GTX 280 but not sure what it'd be like against one of these puppies.
  • dagamer34 - Wednesday, September 23, 2009 - link

    I need my bitstream Dolby Digital TrueHD/DTS HD Master Audio bistreaming codecs!!! :)
  • ew915 - Wednesday, September 23, 2009 - link

    I don't see this beating the GT300 as for so it should beat the GTX295 by a great margin.
  • tamalero - Wednesday, September 23, 2009 - link

    dood, you forgot the 295 is a DUAL CHIP?
  • SiliconDoc - Wednesday, September 23, 2009 - link

    roflmao - Gee no more screaming the 4850x2 and the 4870x2 are best without pointing out the two gpu's needed to get there.
    --
    Nonetheless, this 5870 is EPIC FAIL, no matter what - as we see the disappointing numbers - we all see them, and it's not good.
    ---
    Problem is, Nvidia has the MIMD multiple instructions breakthrough technology never used before that according to reports is an AWESOME advantage, lus they are moving to DDR5 with a 512 bit bus !
    --
    So what is in the works is an absolute WHOMPING coming down on ati that BIG GREEN NVIDIA is going to deliver, and the poor numbers here from what was hoped for and hyped over (although even PREDICTED by the red fan Derek himself in one portion of one sorrowful and despressed sentence on this site) are just one step closer to that nail in the coffin...
    --
    Yes I sure hope ati has something major up it's sleeve, like 512 bit mem bus increased card coming, the 5870Xmem ...
    I find the speculation that ATI "mispredicted" the bandwidth needs to be utter non-sense. They are 2-3 billion in the hole from the last few years with "all these great cards" they still lose $ on every single sale, so they either cannot go higher bit width, or they don't want to, or they are hiding it for the next "strike at NVidia" release.
  • erple2 - Friday, September 25, 2009 - link

    So you're comparing this product with a not yet release product and saying that the not yet released product is going to trounce it, without any facts to back it up? Do you have the hardware? If not, then you're simply ranting.

    Will the GT300 beat out the 5870? I dunno, probably. If it didn't, that would imply that the move from GT200 to GT300 was a major disappointment for NVidia.

    I think that EPIC FAIL is completely ludicrous. I can see "epic fail" applied to the Geforce FX series when it came out. I can also see "epic fail" for the Radeon MAXX back in the day. But I don't see the 5870 as "epic fail". If you look at the card relative to the 4870 (the card it replaces), it's quite good - solid 30% increase. That's what I would expect from a generation improvement (that's what the gt200's did over the 9800's, and what the 8800 did over the 7900, etc).

    BTW, I'm seeing the 5870 as pretty good - it beats out all single card NVidia by a reasonable and measureable amount. Sounds like ATI has done well. Or are you considering anything less than 2x the performance of the NVidia cards "epic fail"? In that case, you may be disappointed with the GT300, as well. In fact, I'll say that the GT300 is a total fail right now. I mean jeez! It scores ZERO FPS in every benchmark! That's super-epic fail. And I have the numbers to back that statement up.

    Since you are making claims about the epic fail nature of the 5870 based on yet to be released hardware, I can certainly play the same game, and epic fail anything you say based on those speculative musings.
  • SiliconDoc - Monday, September 28, 2009 - link

    Well the GT200 was 60.96% increase average. AT says so.

    http://www.anandtech.com/video/showdoc.aspx?i=3334...">http://www.anandtech.com/video/showdoc.aspx?i=3334...

    So, I guess ati lost this round terribly, as NVidia's last just beat them by more than double your 30%.

    Great, EPIC FAIL is correct, I was right, and well...
  • Finally - Wednesday, September 23, 2009 - link

    Team Green foames out of their mouthes. It's funny to watch.
  • SiliconDoc - Wednesday, September 23, 2009 - link

    Glad you are having fun.
    Just let me know when you disagree, and why. I'm certain your fun will be "gone then", since reality will finally take hold, and instead of you seeing foam, I'll be seeing drool.

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