HFW and NVIDIA SER?

[gorba]

This post regards HFW's native shader compilation. NVIDIA has a technology called Shader Execution Reordering (SER). It unlocks the potential for better ray and memory coherency in ray tracing shaders and, thus, increases performance and shading efficiency.

https://developer.nvidia.com/blog/improve-shader-performance-and-in-game-frame-rates-with-shader-execution-reordering/

Here's a video of it in action:
https://www.youtube.com/watch?v=v7GHivwL9dw

And this article is a really good deep dive, albeit technical.

https://chipsandcheese.com/2023/05/16/shader-execution-reordering-nvidia-tackles-divergence/

A few noteworthy quotes:

"Shading divergence is a long-standing problem in ray tracing. With increasingly complex renderer implementations, more workloads are becoming limited by shader execution rather than ray tracing. One way to mitigate this problem is to reduce the divergence affecting the GPU when executing shader code."

"From a developers' point of view, GPU programming APIs look like you're spawning off many independent threads. But under the hood, these threads are organized into groups called wavefronts or warps that run in lockstep. This allows the hardware to use one program counter and instruction opcode to do the math on many data elements, taking advantage of more parallelism without massively bloating instruction control hardware. For example, take the pixel shader below. To render at 4K, it dispatched 8,294,401 (3840*2160 + 1) threads organized into 259,201 wavefronts."

"I'm guessing SER only reorders threads within the SM. That reduces the scope of reordering, making the process faster."

To me, it sounds like SER doesn't replace the CPU as the primary user for shader compilation, but the GPU intercepts and reorganizes how the shader compilation happens, making things more efficient.

Is that correct?
Could HFW benefit from such tech?

[TheWaterBottle]

"...in ray tracing shaders..." HFW doesn't have rtx as far as my knowledge goes sooooo... it might not do anything in this game. BUT don't quote me on that!

[MancSoulja]

Originally posted by TheWaterBottle:

"...in ray tracing shaders..." HFW doesn't have rtx as far as my knowledge goes sooooo... it might not do anything in this game. BUT don't quote me on that!

It has SSR which is technically a technique that uses traced rays but there's no actual ray tracing in the game.

https://lettier.github.io/3d-game-shaders-for-beginners/screen-space-reflection.html

[gorba]

Oh, well, that's... disappointing. Thank you for the info.

[בתאניה]

Game looks amazing without any RT though.

[dgrdsv]

Originally posted by gorba:

To me, it sounds like SER doesn't replace the CPU as the primary user for shader compilation, but the GPU intercepts and reorganizes how the shader compilation happens, making things more efficient.

Is that correct?
Could HFW benefit from such tech?

SER has nothing to do with shader compilation and helps only when tracing rays by making sure that these are less divergent and thus run with a higher h/w utilization.

[Kaldaien]

Ser, this is a Wendy's. It doesn't use Ray Tracing.