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
Comments Locked

327 Comments

View All Comments

  • RubberJohnny - Thursday, September 24, 2009 - link

    Well silicondoc you sure have some hatred for ATI/love for nvidia.

    It's almost as if you work for the green team...

    You seem to have all this time on your hands to go around the net looking for links to spread FUD...sitting on new egg watching these cards come in and out of stock like you have a vested interest in seeing ATI fail...unlike any sane person it appears you want nvidia to have a monopoly on the industry?

    Maybe you are privy to some inside info over at nvidia and know they have nothing to counter the 5870 with?

    Maybe the cash they paid you to spin these BS comments would have been better spent on R&D?
  • SiliconDoc - Thursday, September 24, 2009 - link

    That's a nice personal, grating, insulting ripppp, it's almost funny, too.
    ---
    The real problems remain.
    I bring up this stuff because of course, no one else will, it is almost forbidden. Telling the truth shouldn't be that hard, and calling it fairly and honestly should not be such a burden.
    I will gladly take correction when one of you noticing insulters has any to offer. Of course, that never comes.
    Break some new ground, won't you ?
    I don't think you will, nor do I think anyone else will - once again, that simply confirms my factual points.
    I guess I'll give you a point for complaining about delivery, if that's what you were doing, but frankly, there are a lot of complainers here no different - let's take for instance the ATI Radeon HD 4890 vs. NVIDIA GeForce GTX 275 article here.
    http://www.anandtech.com/video/showdoc.aspx?i=3539">http://www.anandtech.com/video/showdoc.aspx?i=3539
    Boy, the red fans went into rip mode, and Anand came in and changed the articles (Derek's) words and hence "result", from GTX275 wins to ATI4890 wins.
    --
    No, it's not just me, it's just the bias here consistently leans to ati, and wether it's rooting for the underdog that causes it, or the brooding undercurrent hatred that surfaces for "the bigshot" "greedy" "ripoff artist" "nvidia overchargers" "industry controlling and bribing" "profit demon" Nvidia, who knows...
    I'm just not afraid to point it out, since it's so sickening, yes, probably just to me, "I'm sure".
    How about this glaring one I have never pointed out even to this day, but will now:
    ATI is ALWAYS listed first, or "on top" - and of course, NVIDIA, second, and it is no doubt, in the "reviewer's minds" because of "the alphabet", and "here we go in alphabetical order".
    A very, very convenient excuse, that quite easily causes a perception bias, that is quite marked for the readers.
    But, that's ok.
    ---
    So, you want to tell me why I shouldn't laugh out loud when ATI uses NVIDIA cards to develope their "PhysX" competition Bullet ?
    ROFLMAO
    I have heard 100 times here (from guess whom) that the ati has the wanted "new technology", so will that same refrain come when NVIDIA introduces their never before done MIMD capable cores in a few months ? LOL
    I can hardly wait to see the "new technology" wannabes proclaiming their switched fealty.
    Gee sorry for noticing such things, I guess I should be a mind numbed zombie babbling along with the PC required fanning for ati ?
  • silverblue - Thursday, September 24, 2009 - link

    No; if he did work for nVidia, he'd be far better informed and far less prone to using the phrase "red rooster" every five seconds.
  • crackshot91 - Wednesday, September 23, 2009 - link

    Any possibility of benchmarks with a core 2 duo?

    I wanna know if it will be necessary to upgrade to an i5 or i7 (All new mobo) to see big performance gains over my 8800GT. Will a C2D E6750 @ 3.2GHz bottleneck it?
  • Ryan Smith - Wednesday, September 23, 2009 - link

    Our recent Core i7 860 article should do an adequate job of answering that question. Several of the benchmarks were taken right out of this article.
  • therealnickdanger - Wednesday, September 23, 2009 - link

    You dedicated a full page to the flawless performance of its A/V output, but didn't mention it in the "features" part of the conclusion. It's a very powerful feature, IMO. Granted, this card may be a tad too hot and loud to find a home in a lot of HTPCs, but it's still an awesome feature and you should probably append your conclusion... just a suggestion though.

    Ultimately, I have to admit to being a little disappointed by the performance of this card. All the Eyefinity hype and playable framerates at massive 7000x3000 resolutions led me to believe that this single card would scale down and simply dominate everything at the 30" level and below. It just seems logical, so I was taken aback when it was beat by, well, anything else. I expected the 5870 and 5870CF to be at the top of every chart. Oh well.

    Awesome article though! I'm sure there's a 5850 in my future!
  • MrMom - Wednesday, September 23, 2009 - link

    Does anyone have a good explanation why the massive HD5870 is still slower/@par with the GTX295?

    Thanks
  • SiliconDoc - Thursday, September 24, 2009 - link

    Yes, because the ati core "really sucks". It needs DDR5, and much higher MHZ to compete with Nvidia, and their what, over 1 year old core. LOL Even their own 4870x2.
    Or the 3 year old G92 vs the ddr3 "4850" the "topcore" before yesterday. (the ati topcore minus the well done 3m mhz+ REBRAND ring around the 4890)
    That's the sad, actual truth. That's the truth many cannot bear to bring themselves to realize, and it's going to get WORSE for them very soon, with nvidia's next release, with ddr5, a 512 bit bus, and the NEW TECHNOLOGY BY NVIDIA THAT ATI DOES NOT HAVE MIMD capable cores.
    Oh, I can hardly wait, but you bet I'm going to wait, you can count on that 100%.

  • Spoelie - Thursday, September 24, 2009 - link

    because those are 2 480mm² dies, while this is only 1 360mm² die?
  • Griswold - Wednesday, September 23, 2009 - link

    Its one GPU instead of two, maybe?

Log in

Don't have an account? Sign up now