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
AA Image Quality & Performance
With HL2 unsuitable for use in assessing image quality, we will be using Crysis: Warhead for the task. Warhead has a great deal of foliage in parts of the game which creates an immense amount of aliasing, and along with the geometry of local objects forms a good test for anti-aliasing quality. Look in particular at the leaves both to the left and through the windshield, along with aliasing along the frame, windows, and mirror of the vehicle. We’d also like to note that since AMD’s SSAA modes do not work in DX10, this is done in DX9 mode instead.
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AMD Radeon HD 5870
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AMD Radeon HD 4870
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NVIDIA GTX 280
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| No AA | ||
| 2X MSAA | ||
| 4X MSAA | ||
| 8X MSAA | ||
| 2X MSAA +AAA | 2X MSAA +AAA | 2X MSAA + SSTr |
| 4X MSAA +AAA | 4X MSAA +AAA | 4X MSAA + SSTr |
| 8X MSAA +AAA | 8X MSAA +AAA | 8X MSAA + SSTr |
| 2X SSAA | ||
| 4X SSAA | ||
| 8X SSAA |
From an image quality perspective, very little has changed for AMD compared to the 4890. With MSAA and AAA modes enabled the quality is virtually identical. And while things are not identical when flipping between vendors (for whatever reason the sky brightness differs), the resulting image quality is still basically the same.
For AMD, the downside to this IQ test is that SSAA fails to break away from MSAA + AAA. We’ve previously established that SSAA is a superior (albeit brute force) method of anti-aliasing, but we have been unable to find any scene in any game that succinctly proves it. Shader aliasing should be the biggest difference, but in practice we can’t find any such aliasing in a DX9 game that would be obvious. Nor is Crysis Warhead benefitting from the extra texture sampling here.
From our testing, we’re left with the impression that for a MSAA + AAA (or MSAA + SSTr for NVIDIA) is just as good as SSAA for all practical purposes. Much as with the anisotropic filtering situation we know through technological proof that there is better method, but it just isn’t making a noticeable difference here. If nothing else this is good from a performance standpoint, as MSAA + AAA is not nearly as hard on performance as outright SSAA is. Perhaps SSAA is better suited for older games, particularly those locked at lower resolutions?
For our performance data, we have two cases. We will first look at HL2 on only the 5870, which we ran before realizing the quality problem with Source-engine games. We believe that the performance data is still correct in spite of the visual bug, and while we’re not going to use it as our only data, we will use it as an example of AA performance in an older title.
As a testament to the rendering power of the 5870, even at 2560x1600 and 8x SSAA, we still get a just-playable framerate on HL2. To put things in perspective, with 8x SSAA the game is being rendered at approximately 32MP, well over the size of even the largest possible single-card Eyefinity display.
Our second, larger performance test is Crysis: Warhead. Here we are testing the game on DX9 mode again at a resolution of 1920x1200. Since this is a look at the impact of AA on various architectures, we will limit this test to the 5870, the GTX 280, and the Radeon HD 4890. Our interest here is in performance relative to no anti-aliasing, and whether different architectures lose the same amount of performance or not.
Starting with the 5870, moving from 0x AA to 4x MSAA only incurs a 20% drop in performance, while 8x MSAA increases that drop to 35%, or 80% of the 4x MSAA performance. Interestingly, in spite of the heavy foliage in the scene, Adaptive AA has virtually no performance hit over regular MSAA, coming in at virtually the same results. SSAA is of course the big loser here, quickly dropping to unplayable levels. As we discussed earlier, the quality of SSAA is no better than MSAA + AAA here.
Moving on, we have the 4890. While the overall performance is lower, interestingly enough the drop in performance from MSAA is not quite as much, at only 17% for 4x MSAA and 25% for 8x MSAA. This makes the performance of 8x MSAA relative to 4x MSAA 92%. Once again the performance hit from enabling AAA is miniscule, at roughly 1 FPS.
Finally we have the GTX 280. The drop in performance here is in line with that of the 5870; 20% for 4x MSAA, 36% for 8x MSAA, with 8x MSAA offering 80% of the performance. Even enabling supersample transparency AA only knocks off 1 FPS, just like AAA under the 5870.
What this leaves us with are very curious results. On a percentage basis the 5870 is no better than the GTX 280, which isn’t an irrational thing to see, but it does worse than the 4890. At this point we don’t have a good explanation for the difference; perhaps it’s a product of early drivers or the early BIOS? It’s something that we’ll need to investigate at a later date.
Wrapping things up, as we discussed earlier AMD has been pitching the idea of better 8x MSAA performance in the 5870 compared to the 4800 series due to the extra cache. Although from a practical perspective we’re not sold on the idea that 8x MSAA is a big enough improvement to justify any performance hit, we can put to rest the idea that the 5870 is any better at 8x MSAA than prior cards. At least in Crysis: Warhead, we’re not seeing it.
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poohbear - Wednesday, September 23, 2009 - link
is it just me or is anyone else disappointed? next gen cards used to double the performance of previous gen cards, this card beats em by a measly 30-40%. *sigh* times change i guess.AznBoi36 - Wednesday, September 23, 2009 - link
It's just you.The next generations never doubled in performance. Rather they offered a bump in framerates (15-40%) along with better texture filtering, AA, AF etc...
I'd rather my games look AMAZING at 60fps rather than crappy graphics at 100fps.
SiliconDoc - Monday, September 28, 2009 - link
Golly, another red rooster lie, they just NEVER stop.Let's take it right from this site, so your whining about it being nv zone or fudzilla or whatever shows ati is a failure in the very terms claimed is not your next, dishonest move.
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NVIDIA w/ GT200 spanks their prior generation by 60.96% !
That's nearly 61% average increase at HIGHEST RESOLUTION and HIGHEST AA AF settings, and it right here @ AT - LOL -
- and they matched the clock settings JUST TO BE OVERTLY UNFAIR ! ROFLMAO AND NVIDIA'S NEXT GEN LEAP STILL BEAT THE CRAP OUT OF THIS LOUSY ati 5870 EPIC FAIL !
http://www.anandtech.com/video/showdoc.aspx?i=3334...">http://www.anandtech.com/video/showdoc.aspx?i=3334...
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roflmao - that 426.70/7 = 60.96 % INCREASE FROM THE LAST GEN AT THE SAME SPEEDS, MATCHED FOR MAKING CERTAIN IT WOULD BE AS LOW AS POSSIBLE ! ROFLMAO NICE TRY BUT NVIDIA KICKED BUTT !
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Sorry, the "usual" is not 15-30% - lol
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NVIDIA's last usual was !!!!!!!!!!!! 60.69% INCREASE AT HIGHEST SETTINGS !
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Now, once again, please, no lying.
piroroadkill - Wednesday, September 23, 2009 - link
No, it's definitely just youGriswold - Wednesday, September 23, 2009 - link
Its just you. Go buy a clue.ET - Wednesday, September 23, 2009 - link
Should probably be removed...Nice article. The 5870 doesn't really impress. It's the price of two 4890 cards, so for rendering power that's probably the way to go. I'll be looking forward to the 5850 reviews.
Zingam - Wednesday, September 23, 2009 - link
Good but as seen it doesn't play Crysis once again... :DWe shall wait for 8Gb RAM DDR 7, 16 nm Graphics card to play this damned game!
BoFox - Wednesday, September 23, 2009 - link
Great article!Re: Shader Aliasing nowhere to be found in DX9 games--
Shader aliasing is present all over the Unreal3 engine games (UT3, Bioshock, Batman, R6:Vegas, Mass Effect, etc..). I can imagine where SSAA would be extremely useful in those games.
Also, I cannot help but wonder if SSAA would work in games that use deferred shading instead of allowing MSAA to work (examples: Dead Space, STALKER, Wanted, Bionic Commando, etc..), if ATI would implement brute-force SSAA support in the drivers for those games in particular.
I am amazed at the perfectly circular AF method, but would have liked to see 32x AF in addition. With 32x AF, we'd probably be seeing more of a difference. If we're awed by seeing 16x AA or 24x CFAA, then why not 32x AF also (given that the increase from 8 to 16x AF only costs like 1% performance hit)?
Why did ATI make the card so long? It's even longer than a GTX 295 or a 4870X2. I am completely baffled at this. It only has 8 memory chips, uses a 256-bit bus, unlike a more complex 512-bit bus and 16 chips found on a much, much shorter HD2900XT. There seems to be so much space wasted on the end of the PCB. Perhaps some of the vendors will develop non-reference PCB's that are a couple inches shorter real soon. It could be that ATI rushed out the design (hence the extremely long PCB draft design), or that ATI deliberately did this to allow 3rd-party vendors to make far more attractive designs that will keep us interested in the 5870 right around the time of GT300 release.
Regarding the memory bandwidth bottleneck, I completely agree with you that it certainly seems to be a severe bottleneck (although not too severe that it only performs 33% better than a HD4890). A 5870 has exactly 2x the specifications of a 4890, yet it generally performs slower than a 4870X2, let alone dual-4890 in Xfire. A 4870 is slower than a 4890 to begin with, and is dependent on Crossfire.
Overall, ATI is correct in saying that a 5870 is generally 60% faster than a 4870 in current games, but theoretically, a 5870 should be exactly 100% faster than a 4890. Only if ATI could have used 512-bit memory bandwidth with GDDR5 chips (even if it requires the use of a 1024-bit ringbus) would the total memory bandwidth be doubled. The performance would have been at least as good as two 4890's in crossfire, and also at least as good as a GTX295.
I am guessing that ATI wants to roll out the 5870X2 as soon as possible and realized that doing it with a 512-bit bus would take up too much time/resources/cost, etc.. and that it's better to just beat NV to the punch a few months in advance. Perhaps ATI will do a 5970 card with 512-bit memory a few months after a 5870X2 is released, to give GT300 cards a run for its money? Perhaps it is to "pacify" Nvidia's strategy with its upcoming next-gen that carry great promises with a completely revamped architecture and 512 shaders, so that NV does not see the need to make its GT300 exceed the 5870 by far too much? Then ATI would be able to counter right afterwards without having to resort to making a much bigger chip?
Speculation.. speculation...
Lakku - Wednesday, September 23, 2009 - link
Read some of the other 5780 articles that cover SSAA image quality. It actually makes most modern games look worse, but that is through no fault of ATi, just the nature of the SS method that literally AA's everything, and in the process, can/does blur textures.strikeback03 - Wednesday, September 23, 2009 - link
I don't know much about video games, but in photography it is known that reducing the size of an image reduces the appearance of sharpness as well, so final sharpening should be done at the output size.