Mesa 21.1 Released With RADV Variable Rate Shading, More Intel Vulkan Improvements

[phoronix]

Phoronix: Mesa 21.1 Released With RADV Variable Rate Shading, More Intel Vulkan Improvements

Mesa 21.1 is available today as the latest quarterly feature release to this collection of open-source OpenGL and Vulkan drivers. There are many features to show with this new release and it even managed to release on-schedule...

https://www.phoronix.com/scan.php?page=news_item&px=Mesa-21.1-Released

[fagnerln]

It's sad that this VRS is exclusive to rdna2, would be nice if it support polaris as it need a bit more gas.

[fafreeman]

It's sad that this VRS is exclusive to rdna2, would be nice if it support polaris as it need a bit more gas.

its limited to rdna 2 because rdna2 has hardware support for it. polaris does not. so even on windows, vrs is only supported on rdna2. even with nvidia, vrs is only supported on turing and above. pascal lacks it.

i would like to know how mesh shader support in mesa is going. that's another pretty big performance boost. along with sampler feedback.

[BNieuwenhuizen]

i would like to know how mesh shader support in mesa is going. that's another pretty big performance boost. along with sampler feedback.

Mesh shaders and sampler feedback are a bit messy in the sense there is no cross-vendor vulkan extension for them yet. Combined with not really seeing games use it yet they haven't quite been the top priority yet.

[theriddick]

From my understanding VRS can't be tested with proton/wine games? must be native?

[baryluk]

From my understanding VRS can't be tested with proton/wine games? must be native?

Totally can! vkd3d-proton supports VRS for DX12 titles partially since version 2.2, and with 2.3 it is fully supported. RADV VRS was probably mostly tested using vkd3d actually. There are few Vulkan titles that utilize VRS too tho.

[theriddick]

Totally can! vkd3d-proton supports VRS for DX12 titles partially since version 2.2, and with 2.3 it is fully supported. RADV VRS was probably mostly tested using vkd3d actually. There are few Vulkan titles that utilize VRS too tho.

Ok, well I have mesa21.2 and latest vkd3d-proton but not sure how to enable VRS.

[ihatemichael]

- DRM format modifiers support for AMD.

Can someone explain what modifiers are? I hear it all the time.

[tildearrow]

its limited to rdna 2 because rdna2 has hardware support for it. polaris does not. so even on windows, vrs is only supported on rdna2. even with nvidia, vrs is only supported on turing and above. pascal lacks it.

i would like to know how mesh shader support in mesa is going. that's another pretty big performance boost. along with sampler feedback.

How come? Doesn't pixel shading work by spreading the work around GPU cores?
I don't understand why does VRS require hardware support, when we could just do something like this:

- Use depth buffer or something to calculate which pixels to group
- Dispatch pixel shader to GPU cores for each pixel that is not set to downsample
- Dispatch pixel shader to GPU cores for each group of 2x2 pixels that are downsampled
- And so on

[arQon]

I don't understand why does VRS require hardware support

"Because it does". You can certainly emulate it, yes, but without actual HW support the cost of the shader rebinds etc alone would generally cost you more than the simplified shaders save.