PSA: Apply MLAA instead of MSAA especially on AMD GPUs

Yupyup · 2021-04-16 22:50:46

MSAA does a very slow full color clear on every frame for AMD cards in OpenGL games. MSAA is outdated and is only really used in older games or as an alternative option alongside more modern AA techniques. This also goes for MLAA, it's just faster. If FXAA, TAA, SMAA, pretty much any other AA is available, I recommend those instead.
Adriconf allows you to do this easily per-game and is available in the main repo.
Tf2 w/ 32x MLAA on a Vega 8 iGPU: ~190 FPS
Tf2 w/ 4x MSAA on Vega 8 iGPU: ~110 FPS

Lone_Wolf · 2021-04-17 13:09:54

First, something like this should be in wiki, not on forum.

second :
Both framerates look playable , is there a difference in visual quality ?

third
Well designed applications should use techniques like vector graphics to be able to scale things up almost indefinitely .

Incase they use techniques that don't scale well, anti-aliasing could be used to compensate that partially as a resource heavy method.

My preffered solution however is to set the monitor to the resolution the application was designed for.
CRTs were very good with that, lcd screens have more trouble with it.
(Although my fullhd screen does do a reasonable job using hardware to scale down to 800x600 & 640x480 ).

Welcome to arch linux forums and I do hope you'll add a note to the wiki about this.

edit : typos

Last edited by Lone_Wolf (2021-04-18 09:58:26)

Yupyup · 2021-04-18 03:00:53

Lone_Wolf wrote:

First, something like this should be in wiki, not on forum.
second :
Both framerates look playable , is there a difference in visual quality ?
third
Well designed applications should use techniques like vector graphics to be able to scale things up almost indefinetly .
Incase they use techniques that don't scale well, anti-aliasing could be used to compensate that partially as a resource heavy method.
My preffered solution however is to set the monitor to the resolution the application was designed for.
CRTs were very good with that, lcd screens have more trouble with it.
(Although my fullhd screen does do a reasonable job using hardware to scale down to 800x600 & 640x480 ).

Welcome to arch linux forums and I do hope you'll add a note to the wiki about this.

Using dosbox scalers options helps .

Thanks for the warm welcome! I'll put it on the wiki where it seems appropriate. Maybe in "performance" or "mesa"...I'll look around.

Also, some further info:

1. For Tf2, I was benchmarking this at (almost) the lowest settings possible. The "low" preset from mastercomfig with mat_bumpmap and mat_phong enabled as there are rendering issues without them. This is a mesa issue that still hasn't been fixed. At higher settings the difference will definitely be noticeable as Tf2 is a rather poorly optimized game using way too much CPU and not enough GPU. This is a common theme in older source games, Tf2 was just an example. The visual quality is about the same with MLAA maybe being slightly less blurry. MLAA does however apply antialiasing to text which doesn't look nice at higher values and doesn't work with the alpha coverage Tf2 implements that allows MSAA to work on transparent textures.

2. Upscaling, from my understanding, is more expensive than antialiasing for *most* games compared to more efficient antialiasing like TAA or FXAA, albeit usually looks better. In my experience upscaling is faster than MSAA, but that's probably just because MSAA in particular has poor performance with AMD cards on Linux. Antialiasing such as TAA provide more benefits than just smoothing jaggies and makes objects moving at a lower framerate than your refresh rate appear smoother.

Apologies if this is also a bit off topic but the slow full color clear MSAA does only effects Linux and macOS and isn't known about by many people, so some maybe confused as to why games that implement it run much slower than on Windows and I hope this helps someone trying to figure out why if it shows up in search suggestions.

Lone_Wolf · 2021-04-18 10:33:53

There is still hope for msaa improvements[1] , although it's hard to tell if that will benefit older games.

Mesa devs have branched off 21.1 and tagged rc1, but it often takes 4-6 weeks before new stable is released.
Incase you want to know sooner whether things have improved check my aur mesa-git or mesa-minimal-git package.

Keep in mind that the latter requires you to build llvm trunk and this could take several hours depending on your hardware.

https://www.phoronix.com/scan.php?page= … -MSAA-21.1

Last edited by Lone_Wolf (2021-04-18 10:34:22)

Arch Linux

#1 2021-04-16 22:50:46

PSA: Apply MLAA instead of MSAA especially on AMD GPUs

#2 2021-04-17 13:09:54

Re: PSA: Apply MLAA instead of MSAA especially on AMD GPUs

#3 2021-04-18 03:00:53

Re: PSA: Apply MLAA instead of MSAA especially on AMD GPUs

#4 2021-04-18 10:33:53

Re: PSA: Apply MLAA instead of MSAA especially on AMD GPUs

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