View Full Version : Real Life Gaming : 6800 GT & AA investigation

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01-08-05, 01:21 PM
Well guys, I decided to make a thread about how NV applies AA to games. I will post more screens, but i'm basicly going by GTR for now since racing games are ( IMO ) the best to look @ AA quality.

Here is GTR ( demo ) @ 1600x1200 4xAA/16xAF full details ( 71.20 Xtreme G )


Look up the track a little, the boudry lines get no AA at all! The AA gets applied to the track once I reach a certain point, after that, the AA goes away ( take a look @ the rear view mirror )

Here is an example of how the lines get AA...

Far Away:




Another example:


I'm going to test out 8xAA right now...

01-08-05, 09:24 PM
Down loading now to compare using a Radeon 9700Pro since I have the same Nvidia card as you. It could be a game issue, so by testing out with ATI's AA we can see if that is the case. 215mb!!!! Should take about 18min to download, install and start testing on my Rady.

01-08-05, 09:25 PM
Cool, thanks for the help.

01-08-05, 09:37 PM
Downloading the demo now. I will see what sort of output a R420 gives.

It will be a while since KAL-Online is eating up my bandwidth. lol

01-08-05, 09:38 PM
Looking at your examples it looks like in the background there are some things AA'ed, the fence and the house in the background with the image you have marked up. Maybe the game after a given Z distance uses alpha textures or something for the track lines. The download is slowing down, at 67% now. . .

Hey Anzak, your the one slowing down my download ;) 78%

01-08-05, 09:55 PM
Only 55%. I know why the track lines don't have AA applied to them, they are part of a texture and MSAA is only edge based AA meaning it only hits the edges of polys and not textures. Supersampling on the otherhand applies AA to the whole picture including the textures. 8xSAA should help in a lot in this case.

Hey Anzak, your the one slowing down my download ;) 78%

Don't blame me for your crappy connection. ;)

01-08-05, 10:08 PM
Same problem with the track lines using 6x AA on the Raddy, here is an image:


Hey Anzak, beat you to the punch :) with my crapola connection, now the 8xS mode using our good old buddy supper sampling should help clear that up circuitbreak8, post some images if you would.

01-08-05, 10:09 PM
Looks like a game issue :)

01-08-05, 10:14 PM
Looks like an ATI issue since Nvidia cards can do some Super Sampling :). Now lets see how well it looks with SSAA or mix mode applied.

Hey JakUp, how about some SLI loving on this game with the goods applied? With images of course :rolleyes:

01-08-05, 10:32 PM
Same problem with the track lines using 6x AA on the Raddy, here is an image:

Definately not what i'm seeing on my X800.

I'll post screens in 5 minutes

01-08-05, 10:37 PM
Looks like a game issue :)

It's a MSAA issue. Super sampling should smooth the edges out.

Anyways, here is what I get @ 1600x1200 w/ 6xAA and 16xAF. Its not near as bad as what noko got.



01-08-05, 10:41 PM
Here some more X800 screens, 1280x1024, 4xAA (cannot post 1600 screens due to my 17 inch lcd)



01-08-05, 10:47 PM
Alright, after closer investigation I believe the X800 is producing a better picture.


Since the shots were in different locations its not a 100% accurate comparison.

01-08-05, 10:49 PM
Definetely... although the nV card seems to have slightly better AF...

01-08-05, 10:49 PM
huh? why is my AA so, you know crappy! Just tried 6x again, no AI, driver force this time and the same stuff occured, ahhh didn't force AF :), let me go back and try again.

01-08-05, 10:51 PM
@Anzak, try a different camera view. TS did it from the bonnet, you from the nose.

01-08-05, 10:56 PM
The thing is, what resolutions are we comparing. The jaggies in the distance should be less visible at lower resolution.

What I'm trying to say is for example, my desktop (right now) is at 1152x864. The images that were posted at 1600x1200 and 1280x1024 are bigger than my full desktop. However, they're at full stretch. Because they're at full stretch, the 1600x1200 image is bigger than the 1280x1024, so if you compare the one at 1280 with the one at 1600, the jaggies are more condensed on the 1280 one, so hence less visible (I think).

However, there are slightly less jaggies on anzak's 6xAA. Anzak, how playable is GTR at 1600x1200 6xAA 16xAF? On my 6800 GT computer, I get around 60-70fps (I think), but this is just at 1152x864 4xAA 16xAF.

One last thing though. There do seem to be more jaggier in the distance compared to other games right, even on 6800Ultra and X800XT? I think it has to do with how the engine renders it.

01-08-05, 11:00 PM
AF did it, sorry for the lousy jpg but it did clear right up:


This may turn out to be an AF issue, since AF does sample textures. Now I will try on my GT tomorrow making sure optimizations are turned off, AF 16x etc..

01-08-05, 11:10 PM
There do seem to be more jaggier in the distance compared to other games right, even on 6800Ultra and X800XT? I think it has to do with how the engine renders it.

There were more issues posted about "distance jaggies" on 6800 vs X800. Not long ago someone posted this kind of issue in UT2004. Me myself posted 2 comparisons vids in that topic taken from Joint Operations (i have 6800GT&X800), on the Nv vid you can clearly see that shadows projected in the distance are far more jaggied than on the X800, the Nv shadows have a horrible shimmer (in movement) while X800's are smooth.

01-08-05, 11:15 PM
I am beginning to believe that this really isn't a AA issue but an AF issue being angle dependent on both gpu's but ATI and Nvidia angles of choice are different.

01-08-05, 11:24 PM
Definetely... although the nV card seems to have slightly better AF...

Yeah, plus the colors are a little brighter in the nvidia shot.

01-08-05, 11:39 PM
It all has to do with the way the AA sampleing patterns work. The further away, the worse the AA quality gets. That is just how AA works. The only way to fix it is to increase the number of samples, up the resolution, or change the sampeling pattern. It does look like the ATI pattern works slightly better than the nV pattern. IMHO the old 3dfx pattern still holds the crown as far as I'm concerned. A shame they are no longer in business.

01-08-05, 11:45 PM
Damn you fraps! Where is my fps counter?!

1600x1200 w/ 6xAA 16xAF - 90fps to 120fps



ATI does a better job, but it would be hard to make out a difference in game since its so fast paced.

01-09-05, 12:00 AM
Those lines are textures so it's not AA that would affect them, at least not multisample AA. This is the same problem that was brought up in all those shimmer threads. Negative LOD clamp helps reduce the problem a lot, though in some instances it can still be seen even with the clamp.

01-09-05, 12:15 AM
I want a X800XT :(