Mesa's Radeon Vulkan Driver "RADV" Prepares Experimental Mesh Shaders

[phoronix]

Phoronix: Mesa's Radeon Vulkan Driver "RADV" Prepares Experimental Mesh Shaders

Mesa's Radeon Vulkan open-source driver "RADV" is preparing to introduce experimental support for mesh shaders...

https://www.phoronix.com/scan.php?page=news_item&px=RADV-Mesh-Shaders-PR

[Linuxxx]

Hopefully Khronos comes up with a cross-vendor way of implementing mesh shaders (which also performs well enough across the board) soon, so that true "next-gen" only games keep performing well on the Steam Deck for years to come.

Personally, I can't wait to experience Unreal Engine 5-built "S.T.A.L.K.E.R. 2 - Heart of Chernobyl" on the comfort of my couch!

[dlq84]

Mesh Shaders is really exciting. I do wonder if the current gen consoles support that? Because that will dictate when we start seeing it widely adopted by games.

[cb88]

Mesh Shaders is really exciting. I do wonder if the current gen consoles support that? Because that will dictate when we start seeing it widely adopted by games.

Xbox does PS5 doesn't (only has primitive shaders). What consoles dictate is a bit fuzzy... it depends on how much work it is to implement mesh sharers just for PC and what the benefits are.

[dlq84]

Xbox does PS5 doesn't (only has primitive shaders). What consoles dictate is a bit fuzzy... it depends on how much work it is to implement mesh sharers just for PC and what the benefits are.

Ok cool. Since they pretty much have the same chip, I suppose PS5 could enable via a future software update. I know they have their own proprietary alternative do dx and vulkan.

[cb88]

Ok cool. Since they pretty much have the same chip, I suppose PS5 could enable via a future software update. I know they have their own proprietary alternative do dx and vulkan.

No PS5 lacks the hardware to do it fast enough (its a derivation or RDNA1 + RT) instead of RDNA2 also based on what the radv guys are saying RDNA2 itself might not be that performant either for mesh shaders.

[smitty3268]

No PS5 lacks the hardware to do it fast enough (its a derivation or RDNA1 + RT) instead of RDNA2 also based on what the radv guys are saying RDNA2 itself might not be that performant either for mesh shaders.

PS5 has a proprietary Sony hardware block called the Geometry Engine which does something similar to mesh shaders. Might not be quite as good, I'm not sure exactly what the difference is, but cross platform console games will probably be ported to use it and the RDNA2 type mesh shaders on the xbox.

[You-]

Best to leave the PS5 discussion out of here because right now we dont know the capability of the geometry engine. Some have suggested its a step back, others have suggested its a step forward but until it is in use, we will all be guessing.

[shmerl]

I'm a bit confused. So does AMD hardware not support it at all or only RDNA2 does? Or they meant that extensions are non standard and that's the main issue?

[middy]

I'm a bit confused. So does AMD hardware not support it at all or only RDNA2 does? Or they meant that extensions are non standard and that's the main issue?

only rdna 2 has hardware support for it.

though i am very confused about this statement:

The RADV developers also note, "NV_mesh_shader will never be officially supported on RADV, because it performs poorly on AMD hardware. However, we are implementing this extension to get some experience with mesh shader technology. Users should not rely on this support because we are going to remove it if/when a potential cross-vendor extension appears."

How does it perform poorly? Benchmarks have shown mesh shaders doing very well on rdna 2 with the 3dmark benchmark. Example, my results: https://www.3dmark.com/ms/28081
A whopping 1289.5 % increase with it on. 35.80 FPS to 497.48 FPS.

Edit:
To compare it to Nvidia, here is this result with a 3090 FE and a 9900K so similar setup to my 5800x and 6900 XT: https://www.3dmark.com/ms/3009
847.4 % increase, 66.83 FPS to 633.15 FPS

My 6900 XT gets a higher increase with shaders on. Nvidia might have the highest FPS, but they also start off much higher with mesh shaders off. Percentage wise, much higher gain with AMD.