Experimental RADV Code Allows Vulkan Ray-Tracing On Older AMD GPUs

[phoronix]

Phoronix: Experimental RADV Code Allows Vulkan Ray-Tracing On Older AMD GPUs

AMD currently just supports Vulkan ray-tracing with their Radeon RX 6000 series graphics cards while now there is independent work being done on Mesa's unofficial Radeon Vulkan driver (RADV) to allow ray-tracing to work with older generations of GPUs like Vega and Polaris...

https://www.phoronix.com/scan.php?page=news_item&px=RADV-Vulkan-RT-For-Older-GPUs

[JoshuaAshton]

Hey, you should mention Bas in this because he is the real star of the show, I just wrote the lowering of the intrinsic for the older hardware.

Also, I wrote it in nir, not SPIR-V.
Also please don't call me Ashton that's my father's name lol.

[Dunexus]

Also, I wrote it in nir, not SPIR-V

Probably noob question, what is the advantage of writting it in nir instead of SPIR-V ?

[FireBurn]

Hey, you should mention Bas in this because he is the real star of the show, I just wrote the lowering of the intrinsic for the older hardware.

Also, I wrote it in nir, not SPIR-V.
Also please don't call me Ashton that's my father's name lol.

With this being implemented in Nir, would it work for all the drivers ingesting Nir?

[JoshuaAshton]

@Dunexus: Convenience, that's just how all the existing meta stuff is written

@FireBurn: Not entirely, some parts could definitely be adapted for a general purpose implementation though.

[FireBurn]

@FireBurn: Not entirely, some parts could definitely be adapted for a general purpose implementation though.

It would be great to see something like that appear, similar to the soft fp64 implementation that was done, I imagine it will be needed for the software renderers at some point anyway

[hvis]

Nice writeup!

It has a typo or two, though: "Yesteryesterday and yesterday I".

[schmidtbag]

Very cool!
Is there a way to use a secondary GPU (not driving a display) to handle the RT rendering, or would the PCIe overhead of that negate the performance benefits of a 2nd GPU?
I imagine for dual-GPU cards, this could be beneficial.

[Azrael5]

This news proofs that amd cards are not supported as they should. So, Vega and Pascal models will be involved or not on RADVD project?

[simburde]

Very cool!
Is there a way to use a secondary GPU (not driving a display) to handle the RT rendering, or would the PCIe overhead of that negate the performance benefits of a 2nd GPU?
I imagine for dual-GPU cards, this could be beneficial.

I'm not an expert but my guess is that can be problematic/hacky on the driver side. Though it's completely possible to make Vulkan program which would offload RT using shader calculation on dedicated GPU. And before any attempts are made in that direction it won't hurt to see "software" RT performance.