AMD's Radeon HD 5870: Bringing About the Next Generation Of GPUs
by Ryan Smith on September 23, 2009 9:00 AM EST- Posted in
- GPUs
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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Xajel - Wednesday, September 23, 2009 - link
Ryan,I've send a detailed solution for this problem to you ( Aero disabled when running and video with UVD accerelation ), but the basic for all readers here is just install HydraVision & Avivo Video Convertor packages, and this should fix the problem...
Ryan Smith - Wednesday, September 23, 2009 - link
Just so we're clear, Basic mode is only being triggered when HDCP is being used to protect the content. It is not being triggered by just using the UVD with regular/unprotected content.biigfoot - Wednesday, September 23, 2009 - link
Well, I've been looking forward to reading your review of this new card for a little while now, especially since the realistic sounding specs leaked out a week or so ago. My first honest impression is that it looks like it'll be a little bit longer till the drivers mature and the game developers figure out some creative ways to bring the processor up to its full potential, but in the mean time, it looks like I'd have to agree with everyone's conclusion that even 150+GB/s isn't enough memory bandwidth for the beast, I'm sure it was a calculated compromise while the design was still on the drawing board. Unfortunately, increasing the bus isn't as easy as stapling on a couple more memory controllers, they probably would've had to resort back to a wider ring bus and they've already been down that road. (R600 anyone) Already knowing how much more die area and power would've been required to execute such a design probably made the decision rather easy to stick with the tested 4 channel GDDR5 setup that worked so well for the RV770 and RV790. As for how much a 6 or 8 channel (384/512 bit) memory controller setup would've improved performance, we'll probably never know; as awesome as it would be, I don't foresee BoFox's idea of ATI pulling a fast one on nVidia and the rest of us by releasing a 512-bit derivative in short order, but crazier things have happened.biigfoot - Wednesday, September 23, 2009 - link
Oh, I also noticed, they must of known that the new memory controller topology wasn't going to cut it all the time judging from all the cache augmentations performed. But like i said, given time, I'm sure they'll optimize the drivers to take advantage of all the new functionality, I'm betting that 90% of the low level functions are still handled identically as they were in the last generations architecture and it will take a while till all the hardware optimizations like the cache upgrades are fully realized.piroroadkill - Wednesday, September 23, 2009 - link
The single most disappointing thing about this card is the noise and heat.Sapphire have been coming out with some great coolers recently, in their VAPOR-X line. Why doesn't ATI stop using the same dustbuster cooler in a new shiny cover, and create a much, much quieter cooler, so the rest of us don't have to wait for a million OEM variations until there's one with a good cooler (or fuck about and swap the cooler ourselves, but unless you have one that covers the GPU AND the RAM chips, forget it. Those pathetic little sticky pad RAM sinks suck total donkey balls.)
Kaleid - Wednesday, September 23, 2009 - link
Already showing up...http://www.techpowerup.com/104447/Sapphire_HD_5870...">http://www.techpowerup.com/104447/Sapphire_HD_5870...
It will be possible to cool the card quietly...
Dante80 - Wednesday, September 23, 2009 - link
the answer you are looking for is simple. Another, more elaborate cooler would raise prices more, and vendors don't like that. Remember what happened to the more expensive stock cooler for the 4770? ...;)Cookie Monster - Wednesday, September 23, 2009 - link
When running dual/multi monitors with past generation cards, the cards would always run at full 3d clocks or else face instabilities, screen corruptions etc. So even if the cards are at idle, it would never ramp down to the 2d clocks to save power, rending impressive low idle power consumption numbers useless (especially on the GTX200 series cards).Now with RV870 has this problem been fixed?
Ryan Smith - Wednesday, September 23, 2009 - link
That's a good question, and something we didn't test. Unfortunately we're at IDF right now, so it's not something we can test at this moment, either.Cookie Monster - Wednesday, September 23, 2009 - link
It would be awesome if you guys do get some free time to test it out. Would be really appreciated! :)