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.
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TA152H - Monday, May 14, 2007 - link
Fanboy? What a dork.I've had success with ATI, not with NVIDIA, and I know ATI stuff a lot better so it's just easier for me to work with. It's not an irrational like or dislike. I bought one NVIDIA and it was a nightmare. Plus, I'm not as sure they'll be around for very long as I am ATI/AMD, although they had a good quarter, and AMD surely had a dreadful one.
Selling discrete video cards alone might get a lot more difficult with the integration of CPUs, and GPUs.
yyrkoon - Monday, May 14, 2007 - link
You are a fanboy, face it. 'I tried a nVidia card once . . .' How long ago was that ? Who made the card ? Did you have it configured properly? Once?! Details like this are important, and seemily/conviently left out. Anyhow, anyone claiming that nVIdia cards are 'junk' has definate issues with assembling/configuring hardware. I say this because my current system uses a nVidia based card, and is 100% rock solid. 'Person between the chair and keyboard' rings a bell.Ask any Linux user why they refuse to use ATI cards in their system . . . You are also one of these people out there that claims ATI driver support is superior to nVIdias driver support I suppose ? If you have truely been using ATI products for 20 years, then you know ATI has one of the worst reputations on the planet for driver support(and while it may have improved, it is not as good as nVidias still).
Yeah, anyhow, ATI, and nVidia both can have problems with their hardware, it is not based 100% on their architecture, but the OEM releasing the products have a lot of effect here also. There are bad OEMs to buy from here on both sides of the fence, knowing who to stay away from, is half the work when building a PC, and probably had a lot more to do with your alleged 'bad nVIdia card', assuming you actually configured the card properly.
I also had a problem with an nVIdia card once, I bought a brand new GF3 card about 7 years ago, and a few of the older games I had, would not display properly with it. What did I do ? I waited about a month, for a new driver, and the problem was solved. I have also had issues with ATI cards, one of which drew too much power from the AGP slot, and would cause the given system to crash 1-2 times a day. This was a design issue/oversight on ATI's behalf(the card was made by Saphire, who also makes ATIs cards). What did I do ? I replaced the card with an nVIdia card, and the system has been stable since.
So you see, I too can skew things to make anyone look bad also, and in the end, it would only serve to make me look like the dork. But if you want to pay more, for less, that is perfectly fine by me.
Pirks - Monday, May 14, 2007 - link
I've got all problems and crappy drivers (especially Linux ones) only from ATI while nVidia software was always much better in my experience. power hungry noisy monsters made by whom? by ATI! as always :) same shit as with their x1800/x1900 miserable power guzzling seriesdiscrete video cards are not going away any time soon. ever heard of integrated video used in games, besides ones from 2000, like old Quake 2? no? then please continue your lovefest with ATI, but for me - it looks like I'll pass on them this time again - since Radeon 9800Pro they went downhill and continue in that direction. they MAY make a decent integrated CPU/GPU budget-oriented vendor in a future, for all those office folks playing simple 2D office games, but real stuff? nope, ATI is still out of the game for me. let's see if they manage to come back with reincarnation of R300 in future.
ironically, AMD CPUs on the other hand have best price/performance ratio, so intel won't see me as their customer. I wish ATI 3D chips were as good as AMD CPUs in that regard (and overclockers please shut up, I'm not bothering to OC my rig because I don't enjoy benchmark numbers, I enjoy REAL stuff like games, and Intel is out of the game for me as well, at least until their budget single core Conroes are out)
utube545 - Tuesday, May 22, 2007 - link
Get a clue, you fucking cretin.dragonsqrrl - Thursday, August 25, 2011 - link
haha... lol, wow. facepalm.dragonsqrrl - Thursday, August 25, 2011 - link
Damn you're a fail noob of an ATI fanboy. Time has not been kind to the HD2900XT, and now you sound more ridiculous then ever... lol.yzkbug - Monday, May 14, 2007 - link
Not a word about new AVIVO HD and digital sound features?DerekWilson - Wednesday, May 16, 2007 - link
we mentioned this ...on the r600 overview page ...
photoguy99 - Monday, May 14, 2007 - link
First to be clear and I do not condone the title of this article, there's no need to bring racism into this.But my point is NVidia can and will react by making the performance per dollar competitive for the R600 vs 8800GTS.
Once the prices are comparable, why buy a more power hungry part (the ATI)?
This is one disadvantage they can't correct until the next respin.
DrMrLordX - Monday, May 14, 2007 - link
Based on the benchmarks results, the only reason I can see for getting 2900XTs is if a). you don't care about power consumption and b). want to run a Crossfire rig at a lower cost of entry than dual-8800 GTXs or 8800 Ultras.As others have said, some more benchmarks in mature DX10 titles might show who the real winner here is performance-wise, and that holds true for multi-GPU scenarios as well.