More Timothy Lottes goodness:

http://forums.anandtech.com/showpost.ph ... tcount=234

How about some numbers: the majority of the cost associated with TXAA is just the cost of in-game MSAA. To put this in perspective for a game like Battlefield3 which has relatively optimized MSAA support for deferred rendering, on the **mid-range mobile** 650M at 1280x800 I measured a BF3 scene at 18ms/frame with no-AA. Simply turning on 2xMSAA adds 4.4 ms/frame, or using instead 4xMSAA adds 9.2 ms/frame. Other games with deferred rendering are much worse than BF3, and games with forward rendering are much better. The cost of TXAA over just MSAA on this GPU at the same resolution is 0.67 ms/frame for 2x, and 1.34 ms/frame for 4x.

That is what i found. Blackened/nvcookies found a crippling performance hit.

The bur is indeed noticeable and the feature may not be for everyone -- hopefully, as TXAA matures they can improve upon this considering many PC Gamers like clean and sharp! The title was littered with aliasing and quite frankly surprised how good it really looks in motion.

I'd like to help developers get the most out of MSAA with selective super-sampling, etc. The aim here would be that in-game you'd have the option to run with standard MSAA on, then crank up the super-sampling in various ways on a slider which ends at full RGSSAA (with a separate slider for LOD bias). Then for those who like the really sharp view, you just use the in game MSAA-to-RGSSAA with the slider, for those who want the film look, you just toggle on TXAA on top of that.

The real challenge here is getting critical mass so that the developer thinks things like selective super-sampling are important to users. That takes some work, because you need to sell it to the average joe too, who probably has a $100 video card. That average joe running with 1080p or soon retina resolution displays simply isn't going to have the perf at native resolution to super-sample on anything but a simple 2.5D game with no depth complexity or triangle density.

So part of my goal with TXAA was finding a way, like with DVDs or BluRays, that the output content could be up-sampled well so that these higher end techniques could be used on lower end cards if the gamer wanted to trade sharpness. Or alternatively on a GPU which isn't fast enough to enable 4xMSAA at native resolution and hit the 120 Hz you want for input latency in game, TXAA could be used with up-sampling, to get that 120 Hz frame rate .... by now you should realize that I'm a latency snob who doesn't care about sharpness, but hates temporal aliasing.

And one other option, which applies to those who like maximum sharpness with RGSSAA: if 4xRGSSAA has a 400% hit on frame rate, and 4xTXAA in an optimized title has say a 50% hit on frame rate, then in theory you'd be able to run the game with 4xTXAA at 2x the resolution (which would be an effective 300% hit on frame rate), and down-sample to have a performance win with TXAA compared to RGSSAA, and still get the sharpness you are looking for thanks to a new quality down-sampling (and I'm not referring to the relatively poor quality you currently get with the NVIDIA GPU-does-the-scaling driver hack).

Anyway there is a lot of things to do...

I'd like to help developers get the most out of MSAA with selective super-sampling, etc. The aim here would be that in-game you'd have the option to run with standard MSAA on, then crank up the super-sampling in various ways on a slider which ends at full RGSSAA (with a separate slider for LOD bias). Then for those who like the really sharp view, you just use the in game MSAA-to-RGSSAA with the slider, for those who want the film look, you just toggle on TXAA on top of that.