NV40 AA comparison thread - 8xS versus 4x: IQ and performance

OK, well using the system in my sig, I did some benchmarking and testing using 4x RGMS AA and 8xS AA (1x2 supersampling + 4xRGMS) in the 61.36 drivers.

The point of this thread will be comparing Nvidia's 4x and 8xS modes in a variety of games in both performance and IQ, and playability impressions.

General benefits of 8xS

CRT users - You can play with higher refresh rates at 1024x768 or 1280x1024/960 than at 1600x1200

LCD users - your native refresh rate probably is 1280x1024, not 1600x1200 - 8xS would allow you to play with higher quality AA.

Also, in general some games have smaller HUDs or text in 1600x1200, and with 8xS you could play those games at a lower res and still get nice looking foliage.

Lastly, 8xS can clean up aliased textures, which often is seen as foliage (trees, bushes, etc) in game, while no amount of multisampling (i.e. not even 32x) would be able to clean up these textures.
***

In general, 8xS costs a lot of performance. In fact, when I benchmarked with Painkiller, 1024x768 with 8xS AA/8xAF performed nearly the same as 1600x1200 with 4xAA/8xAF. One may then question the usefulness of 8xS, but there will be quite a few situations where it may be more useful than any form of multisampling.

The first is Call of Duty. I found that 1280x1024 was playable with 8xS with my below rig, and I also found that it's quality was better than 1600x1200 with 4x. Here are some comparison pics for COD:

Mouseover is 8xS.

Shots are full trilinear with 8xAF, taken using CoD's ingame screenshot dump.

1024x768 - 4x versus 8xS
http://www.reflectonreality.com/images/nv40/1024768/cod.html

1280x1024 - 4x versus 8xS
http://www.reflectonreality.com/images/nv40/12801024/cod.html

1600x1200 - 4x versus 8xS
http://www.reflectonreality.com/images/nv40/16001200/cod.html


So despite being able to play 1600x1200 at 4xAA/8xAF, I found that 1280x1024 with 8xS actually looked better due to all the foliage.

1280x1024 8xS:
http://www.reflectonreality.com/images/nv40/12801024/codss.jpg

1600x1200 4x (note the shimmering barbed wire and lower quality trees)
http://www.reflectonreality.com/images/nv40/16001200/cod4x.jpg

The improvements seen in the above 8xS screenshot would not be possible with any amount of multisampling anti aliasing.

Next up is Painkiller. I need to do some more testing but right now it looks like 8xS really isn't going to benefit much in painkiller since there isn't much foliage that I've seen.

FarCry looks like it will see huge benefits from 8xS, but my current drivers won't override the games AA, and I'm not sure how to set 8xS in the game (don't think its possible). With FarCry and the SM3.0 patch, we will probably see 1024x768 or 1280x1024 at best being playable with 8xS, but with all of the foliage in that game it is possible that like CoD, the lower res with 8xS may look better than the higher res with any level of multisampling.

Anyway I'll post to this thread again once I get more comparisons.

good information there - thanks

Image Quality is much more important than FPS. If you value immersion in gameplay such as in MMORPGs, this is a feature you need.

I haven't seen 8x on an NV card, but I have run 16x on a Parhelia. I'd literally forget what mode I was running in. It's that smooth. The FAA algorithm did occasionally miss an edge (meaning no AA at all) but it was almost always an "inside" edge, and I'd almost never notice it unless I looked.
As cool as it was, I think it's a dead technology though. FAA works by only applying AA to the edges of polygons, but polygon counts keep going up, and they're getting to the point that most of the screen is edges in some games. The grass in Far Cry comes to mind.
I'll be seeing that 8x soon. Hopefully it's close to as good as 16x on a Parhelia. I'm getting a 6800GT as soon as I get a new job.

Great Work!

The 6800's also support a new 16xS AA. Its the very first 16xAA available under a D3D environment. Its consists of 4x RGMS + 2x2 OGSS.

Here is a shot of 4xAA/16xAF(RGMS):

http://www.nvnews.net/articles/chrisray_iq/4xAA.png

And now a shot of 16xS/16xAF:

http://www.nvnews.net/articles/chrisray_iq/16xS.png

It removes aliasing better than any other mode nvidia offers and also sharpens textures. It has a heavy hit on performance though.

Great thread! Let me just add that Call of Duty on the 6800GT is unbelievable, I was simply amazed on how much I could turn things up and how fast this thing would fly. It's like a brand new game. Outstanding job by Nvidia!