ATI Radeon HD 2900 XT: Calling a Spade a Spade
by Derek Wilson on May 14, 2007 12:04 PM EST- Posted in
- GPUs
The New Video Decode Pipeline: UVD
UPDATE: Since the launch of the HD 2900 XT, we've learned that all HD 2000 series parts except the high end R600 based parts will have UVD. This means that the HD 2900 XT will feature the same video decode acceleration offered on the R5xx hardware. As higher end cards are usually paired with faster CPUs, AMD feels that UVD on R600 is unnecessary.
This comes as a bit of a surprise to us and to certain board partners who's box art claims UVD as a feature of the HD 2900 XT. We do apologize for any confusion we may have caused at launch.
NVIDIA beat AMD to the punch with their full H.264 decode acceleration on G86/G84. Of course, AMD is one upping NVIDIA this time around, as their UVD (Unified Video Decode) architecture is also capable of decoding VLC bitstreams on all three HD media codecs. This means that there are no cases where AMD hardware will not handle 100% of the video decode process (after the CPU has dealt with pulling the encrypted content off the disk and preparing it to send to the GPU that is).
Here's a diagram of the landscape as it stands now. Notice that G80 is not capable of the bitstream decode or the inverse transformation (either iDCT or otherwise), but G84/G86 come very close to matching AMD's capabilities.
At the same time, we should remember that bitstream decode is only really heavy under H.264. Certainly VC-1 and MPEG-2 will see some benefit, but they are already fairly manageable. NVIDIA stated that building the hardware to handle VLC bitstreams wouldn't have a high enough return on investment. AMD, however, indicated that their bitstream processors are at least a little bit adaptable and it wasn't that difficult to include VLC decode.
Either way, the best way to figure out what's going on is to take a look at performance and see if there really is any advantage to R600 over G86. Unfortunately, try as we might, we could not get UVD to work with the current drivers provided by AMD and the PowerDVD release that is supposed to enable the hardware acceleration on HD 2000 series parts. We will have to take a second look at hardware decode when AMD and CyberLink or Intervideo get their software in order.
For now, our information leads us to believe that performance won't be hugely improved over G84/G86 in MPEG-2 and VC-1 CPU offloading. Where we might start to see a difference is in AMD's 65nm HD 2000 and mobility series parts. These have the potential to decrease power consumption by large amounts and provide quiet running systems for HTPCs, or longer battery life for notebooks. We will have to wait to get our hands on the higher volume R6xx based parts though. Also worth nothing is that AMD's high-end hardware does something that NVIDIA's 8800 series cards currently don't, so NVIDIA users that want fast H.264 decoding support are stuck with slower 3D performance.
Facebook
Twitter
RSS
86 Comments
View All Comments
GoatMonkey - Monday, May 14, 2007 - link
That's obviously BS. This IS their high end part, it just doesn't perform as well as nVidia's high end part, so it is priced accordingly.poohbear - Monday, May 14, 2007 - link
sweet review though! thanks for including all the important and pertinent cards in your roundup (the 8800gts 320mb inparticular). also love how neutral Anand is in their reviews, unlike some other sites.:pCreig - Monday, May 14, 2007 - link
The R600 is finally here. I'm sure the overall performance is not what AMD was hoping for. Nobody ever shoots to have their newest product be the 2nd best. But pricing it at $399 and including a very nice game bundle will make the HD 2900 XT a VERY worthwhile purchase. I also have the feeling that there is a significant amount of performance increase to be realized through future driver releases ala X1800XT.shady28 - Tuesday, May 15, 2007 - link
Nvidia has gone over the cliff on pricing.
I know of no one personally who has an 88xx series card. I know one who recently picked up an 8600 of some kind, that's it. I have the best GPU of anyone I know.
It's a real shame that there is so much focus on graphics cards that virtually no one buys. These are niche products folks - yet 'who is best' seems to be totally dependent on these niche products. That's patently ridiculous.
It's like saying, since IBM makes the fastest computers in the world (they do), they're the best and you should be buying IBM (or now, lenovo) laptops and desktops.
No one ever said that sort of thing because it's patently ridiculous. Why do people say it now for graphics cards? The fact that they do says a lot about the mentality of sites like AT.
DerekWilson - Tuesday, May 15, 2007 - link
We don't say what you are implying, and we are also very upset with some of NVIDIA's pricing (specifically the 8800 ultra)the 8800 gts 320mb is one of the best values for your money anywhere and isn't crazy expensive -- it's actually the card I'd recommend to anyone who cares about graphics in games and wants good quality and performance at 1600x1200.
I would never tell anyone to buy an 8600 gts because nvidia has the fastest high end card. In fact, in this article, I hope I made it clear that AMD has the opportunity to capitalize on the huge performance gap nvidia left between the 8600 and 8800 series ... If AMD builds a part that performs in this range is priced competitively, they'll have our recommendation in a flash.
Recommending parts based on value at each price or performance segment is something we take pride in and will always do, no matter who has the absolute fastest hardware out there.
The reason our focus was on AMD's fastest part is because they haven't given us any other hardware to test. We will absolutely be talking a lot and in much depth about midrange and budget hardware when AMD makes these parts available to us.
yacoub - Monday, May 14, 2007 - link
$400 is a lot of money. Not terribly long ago the highest end GPU available didn't cost more than $400. Now they hit $750 so you start to think $400 sounds cheap. It's really not. It's a heck of a lot of money for one piece of hardware. You can put together a 650i SLI rig with 2GB of DDR2 6400 and an E4400 for that much money. I know because I just did that. I kept my 7900GT from my old rig because I wanted to see how R600 did before purchasing an 8800GTS 640MB. Now that we've seen initial results I will wait to see how R600 does with more mature drivers and also wait to see the 640MB GTS price come down even more in the meantime.vijay333 - Monday, May 14, 2007 - link
http://www.randomhouse.com/wotd/index.pperl?date=1...">http://www.randomhouse.com/wotd/index.pperl?date=1..."the expression to call a spade a spade is thousands of years old and etymologically has nothing whatsoever to do with any racial sentiment."
yacoub - Monday, May 14, 2007 - link
Yes, a spade was a shovel long before muslims enslaved europeans to do hard labor in north africa and europeans enslaved africans to do hard labor in the 'new world'.vijay333 - Monday, May 14, 2007 - link
whoops...replied to the wrong one.rADo2 - Monday, May 14, 2007 - link
It is not 2nd best (after 8800ULTRA), not 3rd best (after 8800GTX), not 4th best (after 8800GTX-640), but 5th best (after 8800GTS-320), or even worse ;)Bad performance with AA turned on (everybody turns on AA), huge power consumption, late to the market.
A definitive failure.