Why ATI's AA sucks!

[yhelothar]

http://www.firingsquad.com/hardware/geforce_6800_performance_and_overclocking/page3.asp

I've noticed this a lot in racing games where the lines on the roads are always extremely aliased on my 9800Pro. ATI's RGSAA may be great for making the smoothest edges, but what good is it when it doesn't smooth out all edges?

 

[BFG10K]

Uh, why aren't they running the Radeon at 6xAA?

 

[GeneralGrievous]

Because 6xAA utterly cripples any card out there with little noticable benefits.

 

[BFG10K]

Acually no, it doesn't. In fact in the case of the R3xx it doesn't really slow down performance that much but the IQ is better.

 

[GeneralGrievous]

Well at 1600x1200 I can't notice 6xAA at all. I benched it on my XT and lost at least 10% performance each time.

 

[BFG10K]

Well at 1600x1200 I can't notice 6xAA at all.

I fail to see how that's relevant to anything.

I benched it on my XT and lost at least 10% performance each time.

I wouldn't class a 10% performance hit as "utterly crippling".

 

[vshah]

comparing ati's 6x to nvidia's 4x wouldn't really be fair would it?

6x vs. 8xs would be more fair (max mode for each card) and 8xs has higher IQ there due to supersampling (i agree its way too slow)

-Vivan

 

[BFG10K]

comparing ati's 6x to nvidia's 4x wouldn't really be fair would it?

It depends. If the performance is the same or similar then why not?

Also the original poster was complaining about aliasing on his card.

 

[Ages120]

Um isn't that runway a texture. I don't think they model the lines in the road. Wouldn't anistropic texturing clean that up more then anti aliasing. I would be able to determine what exactly is going on if there screen shot links actually took me to a site with a screenshot.

See when they get to where they show the wing edge and shadow the ati looks much better. Might be Nvidia using a multi sampling pixel shader using sub pixel precision or I don't know what can't look at the link with no aa. Freaking joke how some of the most proffessional sites often have the most problems.

 

[Pete]

Yes, I'm almost positive any flat road is a texture in even the most current games, and I'm surprised Brandon continues to mistake AA the culprit, rather than ATi's poorer texture filtering (of which much has been written recently: 3DCenter and Digit-Life have the most detailed articles on ATi's [refrast-level] 5-bit filtering, vs. nV's superior 8-bit). I see texture shimmer out the wazzoo on my 9100, and I suspect a GF4 would show much less of it b/c of its higher-precision filtering.

 

[yhelothar]

Yes it is a texture. As I stated in my OP, ATI's AA is flawed because it only antialiases edges, which textures will remain looking aliased. nVIDIA's AA on the other hand, will antialias everything, which produces a much better output, clearly shown in those screenshots.

That said, I'm a week away from trading this unstable POS 9800Pro to a FX5900Ultra. I miss the stability of my old FX5900..

 

[Ages120]

Should sell the 9800 and upgrade to a 6800

 

[yhelothar]

Sure if you should give me $200 then I shall
kthnx

 

[Ages120]

Whore your self out to 20 women for 10 bucks a pop or one really fat one for $200. Fat girls need loving too.

I think I watch to much family guy. Only show that has some good jokes. Simpsons sucks and every comic I see on comedy central seems either amused by the simplest things or thinks observational humor is actually funny instead of being stupidly obvious.

 

[yhelothar]

I'm a small asian guy... asian chicks don't do whoring, white chicks don't go for asian guys, and a fat chick would crush me, so I'm outta luck

 

[Pete]

nV doesn't AA textures with the 6800 until you hit 8xAA, at which point your framerate falls into the toilet in recent games. Both nV and ATi offer MSAA at 2x and 4x, which means edge-only. ATi's 6x is still MSAA (thus it's relatively small performance hit), and nV's 8x is MSAA + SSAA (thus it's Xobx hueg performance hit).

To reiterate:

SSAA = full-scene (everything: textures, edges, shaders, oh my), big performance hit (it basically renders at X times the resolution, then downsamples to screen res).
MSAA = edge-only (no textures), smaller performance hit.

 

[Blastman]

NV?s 8xAA may have more coverage in some situations, but it?s a slide show on even the 6800 ?

http://www.xbitlabs.com/articles/video/display/r420_21.html

 

[Robor]

Originally posted by: virtualgames0
I'm a small asian guy... asian chicks don't do whoring, white chicks don't go for asian guys, and a fat chick would crush me, so I'm outta luck

That's gotta be one of the funniest things I've read in a while!

 

[Genx87]

I noticed this and thought wow, that looks horrible!

 

[VIAN]

Uh, why aren't they running the Radeon at 6xAA?

I don't think it cripples the card, but the effect is very unnoticeable and is only their to get rid of nasties - such as in the game Mafia, in the harbor with the stacks of wood.

Yes, I'm almost positive any flat road is a texture in even the most current games, and I'm surprised Brandon continues to mistake AA the culprit, rather than ATi's poorer texture filtering (of which much has been written recently: 3DCenter and Digit-Life have the most detailed articles on ATi's [refrast-level] 5-bit filtering, vs. nV's superior 8-bit). I see texture shimmer out the wazzoo on my 9100, and I suspect a GF4 would show much less of it b/c of its higher-precision filtering.

I know, I used both cards and this has to be my only real complaint. Sometimes, I think that ATI's confidence is too confident. They don't have the best picture quality ever. It must be one of their performance gaining optimizations or something.

NV?s 8xAA may have more coverage in some situations, but it?s a slide show on even the 6800 ?

It's a sad thing too because it really looks nice.

 

[Insomniak]

Originally posted by: virtualgames0
http://www.firingsquad.com/hardware/geforce_6800_performance_and_overclocking/page3.asp

I've noticed this a lot in racing games where the lines on the roads are always extremely aliased on my 9800Pro. ATI's RGSAA may be great for making the smoothest edges, but what good is it when it doesn't smooth out all edges?

Both ATi and Nvidia are using RGAA now, so unhappy all around for you. Personally, I think it looks much better.

 

[BFG10K]

Wouldn't anistropic texturing clean that up more then anti aliasing.

More than likely.

I see texture shimmer out the wazzoo on my 9100,

Try 16xAF with a LOD of 0. In any case the R2xx's AF is definitely inferior to that of the R3xx and higher.

nVIDIA's AA on the other hand, will antialias everything,

Only the xS modes which at this stage is only the very slow 8x.

I don't think it cripples the card, but the effect is very unnoticeable and is only their to get rid of nasties - such as in the game Mafia, in the harbor with the stacks of wood.

There is a difference between 6xAA and 4xAA. Not only that but your comment is completely contradictory, almost like you changed your mind halfway through posting it.

It's a sad thing too because it really looks nice.

It only looks better on alpha textures. On edges ATi's 6xAA still has the edge (excuse the pun!).

 

[VIAN]

There is a difference between 6xAA and 4xAA. Not only that but your comment is completely contradictory, almost like you changed your mind halfway through posting it.

OK, normally, you won't notice a difference between 6xAA and 4xAA, if there is a difference, it is very little and hard to find. There are certain situations however where you notice 6xAA has a better effect than 4xAA and that is in that Mafia level I mentioned above. There is much shimmering with 4xAA and much less shimmering with 6xAA.

 

[Pete]

Originally posted by: BFG10K

I see texture shimmer out the wazzoo on my 9100,

Try 16xAF with a LOD of 0. In any case the R2xx's AF is definitely inferior to that of the R3xx and higher.

Would that require more mucking about than RadLinker? Because that seems like an awful lot of trouble to avoid texture shimmer. BTW, I see the shimmer even with simply trilinear, so I'm not sure AF will help. Lowering the LOD probably will, though.

 

[BFG10K]

OK, normally, you won't notice a difference between 6xAA and 4xAA

That depends entirely on the situation; some situations will show much larger differences than others.

The point is that for a ~10% performance hit it's a no brainer to always use it instead of 4x, especially if someone is complaining about IQ at 4x.

Would that require more mucking about than RadLinker?

You should be able to do it in the registry. Alternatively you can either try lowering the mip-map slider a notch or better yet, find a game that supports LOD adjustments (such as the Unreal games) and test whether that helps. Try 0, 0.5 and 1.

BTW, I see the shimmer even with simply trilinear, so I'm not sure AF will help.

I find shimmer is significantly reduced with 16xAF combined with high resolutions, but again the R200 does have inferior AF quality to the R3xx so YMMV.