Image Quality & AA

When it comes to image quality, the big news from NVIDIA for Fermi is what NVIDIA has done in terms of anti-aliasing of fake geometry such as billboards. For dealing with such fake geometry, Fermi has several new tricks.

The first is the ability to use coverage samples from CSAA to do additional sampling of billboards that allow Alpha To Coverage sampling to fake anti-alias the fake geometry. With the additional samples afforded by CSAA in this mode, the Fermi can generate additional transparency levels that allow the billboards to better blend in as properly anti-aliased geometry would.

The second change is a new CSAA mode: 32x. 32x is designed to go hand-in-hand with the CSAA Alpha To Coverage changes by generating an additional 8 coverage samples over 16xQ mode for a total of 32 samples and giving a total of 63 possible levels of transparency on fake geometry using Alpha To Coverage.

In practice these first two changes haven’t had the effect we were hoping for. Coming from CES we thought this would greatly improve NVIDIA’s ability to anti-alias fake geometry using cheap multisampling techniques, but apparently Age of Conan is really the only game that greatly benefits from this. The ultimate solution is for more developers of DX10+ applications to enable Alpha To Coverage so that anyone’s MSAA hardware can anti-alias their fake geometry, but we’re not there yet.

So it’s the third and final change that’s the most interesting. NVIDIA has added a new Transparency Supersampling (TrSS) mode for Fermi (ed: and GT240) that picks up where the old one left off. Their previous TrSS mode only worked on DX9 titles, which meant that users had few choices for anti-aliasing fake geometry under DX10 games. This new TrSS mode works under DX10, it’s as simple as that.

So why is this a big deal? Because a lot of DX10 games have bad aliasing of fake geometry, including some very popular ones. Under Crysis in DX10 mode for example you can’t currently anti-alias the foliage, and even brand-new games such as Battlefield: Bad Company 2 suffer from aliasing. NVIDIA’s new TrSS mode fixes all of this.


Bad Company 2 DX11 Without Transparency Supersampling


Bad Company 2 DX11 With Transparency Supersampling

The bad news is that it’s not quite complete. Oh as you’ll see in our screenshots it works, but the performance hit is severe. It’s currently super-sampling too much, resulting in massive performance drops. NVIDIA is telling us that this should be fixed next month, at which time the performance hit should be similar to that of the old TrSS mode under DX9. We’ve gone ahead and taken screenshots and benchmarks of the current implementation, but keep in mind that performance should be greatly improving next month.

So with that said, let’s look at the screenshots.

NVIDIA GeForce GTX 480 NVIDIA GeForce GTX 285 ATI Radeon HD 5870 ATI Radeon HD 4890
0x 0x 0x 0x
2x 2x 2x 2x
4x 4x 4x 4x
8xQ 8xQ 8x 8x
16xQ 16xQ DX9: 4x DX9: 4x
32x DX9: 4x DX9: 4x + AAA DX9: 4x + AAA
4x + TrSS 4x DX9: 4x + TrSS DX9: 4x + SSAA  
DX9: 4x      
DX9: 4x + TrSS      

With the exception of NVIDIA’s new TrSS mode, very little has changed. Under DX10 all of the cards produce a very similar image. Furthermore once you reach 4x MSAA, each card producing a near-perfect image. NVIDIA’s new TrSS mode is the only standout for DX10.

We’ve also include a few DX9 shots, although we are in the process of moving away from DX9. This allows us to showcase NVIDIA’s old TrSS mode, along with AMD’s Adapative AA and Super-Sample AA modes. Note how both TrSS and AAA do a solid job of anti-aliasing the foliage, which makes it all the more a shame that they haven’t been available under DX10.


Click to Enlarge


Click to Enlarge

When it comes to performance, keep in mind that both AMD and NVIDIA have been trying to improve their 8x MSAA performance. When we reviewed the Radeon 5870 back in September we found that AMD’s 8x MSAA performance was virtually unchanged, and 6 months later that still holds true. The performance hit moving from 4x MSAA to 8x MSAA on both Radeon cards is roughly 13%. NVIDIA on the other hand took a stiffer penalty under DX10 for the GTX 285, where there it fell by 25%. But now with NVIDIA’s 8x MSAA performance improvements for Fermi, that gap has been closed. The performance penalty for moving to 8x MSAA over 4x MSAA is only 12%, putting it right up there with the Radeon cards in this respect. With the GTX 480, NVIDIA can now do 8x MSAA for as cheap as AMD has been able to

Meanwhile we can see the significant performance hit on the GTX 480 for enabling the new TrSS mode under DX10. If NVIDIA really can improve the performance of this mode to near-DX9 levels, then they are going to have a very interesting AA option on their hands.

Last but not least, there’s anisotropic filtering quality. With the Radeon 5870 we saw AMD implement true angle-independent AF and we’ve been wondering whether we would see this from NVIDIA. The answer is no: NVIDIA’s AF quality remains unchanged from the GTX200 series. In this case that’s not necessarily a bad thing; NVIDIA already had great AF even if it was angle-dependant. More to the point, we have yet to find a game where the difference between AMD and NVIDIA’s AF modes have been noticeable; so technically AMD’s AF modes are better, but it’s not enough that it makes a practical difference


GeForce GTX 480


GeForce GTX 285


Radeon 5870

Compute The Test
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  • bala_gamer - Friday, April 02, 2010 - link

    Did you guys recieve the GTX480 earlier than other reviewers? There were 17 cards tested on 3 drivers and i am assuming tests were done multiple times per game to get an average. installing, reinstalling drivers, etc 10.3 catalyst drivers came out week of march 18.

    Do you guys have multiple computers benchmarking at the same time? I just cannot imagine how the tests were all done within the time frame.
    Reply
  • Ryan Smith - Sunday, April 04, 2010 - link

    Our cards arrived on Friday the 19th, and in reality we didn't start real benchmarking until Saturday. So all of that was done in roughly a 5 day span. In true AnandTech tradition, there wasn't much sleep to be had that week. ;-) Reply
  • mrbig1225 - Tuesday, April 06, 2010 - link

    I felt compelled to say a few things about nvidia’s Fermi (480/470 GTX). I like to always start out by saying…let’s take the fanboyism out of the equation and look at the facts. I am a huge nvidia fan, however they dropped the ball big time. They are selling people on ONE aspect of DX11 (tessellation) and that’s really the only thing there cards does well but it’s not an efficient design. What people aren’t looking at is that their tessellation is done by the polymorh engine which ties directly into the cuda cores, meaning the more cuda cores occupied by shaders processing…etc the less tessellation performance and vice versa = less frames per sec. As you noticed we see tons of tessellation benchmarks that show the gtx 480 is substantially faster at tessellation, I agree when the conditions suite that type of architecture (and there isn’t a lot of other things going on). We know that the gf100(480/470gtx) is a computing beast, but I don’t believe that will equate to overall gaming performance. The facts are this gpu is huge (3billion + transistors), creates a boat load of heat, and sucks up more power than any of the latest dual gpu cards (295gtx, 5970) came to market 6 months late and is only faster than its single gpu competition by 10-15% and some of us are happy? Oh that’s right it will be faster in the future when dx11 is relevant…I don’t think so for a few reasons but ill name two. If you look at the current crop of dx11 games, the benchmarks and actual dx11 game benchmarks (shaders and tessellation…etc) shows something completely different. I think if tessellation was nvidia’s trump card in games then basically the 5800 series would be beat substantially in any dx11 title with tessellation turned on…we aren’t seeing that(we are seeing the opposite in some circumstances), I don’t think we will. I also am fully aware that tessellation is scalable, but that brings me to another point. I know many of you will say that it is only in extreme tessellation environments that we really start to see the nvidias card take off. Well if you agree with that statement then you will see that nvidia has another issue. The 1st is the way they implement tessellation in their cards (not very scalable imo) 2nd is, the video card industry sales are not comprised of high end gpus, but the cheaper mainstream ones. Since nvidia polymorph engine is tied directly to its shaders…u kinda see where this is going, basicly less powerful cards will be bottlenecked by their lack of shaders for tessellation and vice versa. Developers want to make money, the way they make money is selling lots of games, example crysis was a big game, however it didn’t break any records sales…truth of the matter is most people systems couldn’t run crysis. Now you look at valve software and a lot of their titles sale well because of how friendly it is to mainstream gpus(not the only thing but it does help). The hardware has to be there to support a large # of game sales, meaning that if the majority of parts cannot do extreme levels of tessellation then you will find few games to implement it. Food for thought… can anyone show me a dx11 title that the gtx480 handily beats the 5870 by the same amount that it does in the heaven benchmark or even close to that. I think as a few of you have said, it will come down to what game work better with what architecture..some will benefit nvidia(Farcry2..good example) others Ati (Stalker)…I think that is what we are seeing now. IMO
    P.S. I think also why people are pissed is because this card was stated to be 60% faster than the 5870. As u can see its not!!
    Reply
  • houkouonchi - Thursday, April 08, 2010 - link

    Why the hell are the screenshots showing off the AA results in a lossy JPEG format instead of PNG like pretty much anything else? Reply
  • dzmcm - Monday, April 12, 2010 - link

    I'm not familiar with Battleforge firsthand, but I understood it uses HD Ambient Occlusion wich is a variation of Screen Space Ambient Occlusion that includes normal maps. And since it's inception in Crysis SSAO has stood for Screen Space AO. So why is it called Self Shadow AO in this article?

    Bit-tech refers to Stalker:CoP's SSAO as "Soft Shadow." That I'm willing to dismiss. But I think they're wrong.

    Am I'm falling behind with my jargon, or are you guys not bothering to keep up?
    Reply
  • nyran125 - Monday, April 12, 2010 - link

    Im going wiht the less power hungry ati 5000 series. I know a 5850 card will easily fit in my Case aswell. There no way id choose the GTX 470 over any of the ati s870 or 5850 cards. So that only leaves the GTX 480 against either the 5870 or the 5850. The performance increase and power increase is NOT worth me paying for a nvidia card thats higher in price over the 5870.

    I meen even looking at the games. The games ill probably play Crysis adn BAttlefield bad company 2 come out on top of the nivdia 480 GTX. so bla.

    Nvidia you need to make a much bette rcard than that fo rme to spend money on a GTX 470 or GTX 480 ove rthe 5870 or 5850.
    Reply
  • nyran125 - Monday, April 12, 2010 - link

    oh and secondly, if your buying a 200 series nivida card or the GTX 480 it isnt fast enough to future proof your computer. You might aswell go spend less money on a 5970 or a single 5870 you know it will last for the next 2 years and the GTX 480 will NOT last any longer than teh 5000 series with its 10-15% performance increase. I didnt like the 200 series nvidia cards and im not interested in even MORE power hungry cards that. I want less power hungry cards and efficiency. To me a game plays bugger all different with 60 FPS average and 100 fps average. If you have a 200 series card save your money and wait for the next gen of cards or at least wait till a DX 11 game actualyl comes out not just Just cause friggin 2.. Reply
  • vagos - Thursday, April 15, 2010 - link

    ok all theese cards are nice. new technology is very welcome. but where is the games to push them?? if i spent 400$ or 500$ on a new card where i could see a really big difference against my old 8800GT?? they sell hardware without software to support it...2 or 3 games makes no difference to me. ps3 an xbox360 have very old graphic cards compared to ati 5800 series and nvidia 400 and still tha games are looking beautifull. an in some cases mauch better than on pc...
    make new games for pc and then i will buy a new card! until then i will stuck with my xbox360...
    Reply
  • Drizzit101 - Sunday, May 09, 2010 - link

    I have been running the GTX 295. The plan was to buy a second GTX 295. Looking at the prices, I was thinking about just buying two GTX 470's. What the better move? Reply
  • Krazy Glew - Tuesday, May 11, 2010 - link

    See http://semipublic.comp-arch.net/wiki/Poor_Man%27s_...

    In particular
    US patent 7,117,421, Transparent error correction code memory system and method,
    Danilak,
    assigned to Nvidia,
    2002.

    http://semipublic.comp-arch.net/wiki/Poor_Man%27s_...
    Reply

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