GPU Ray Tracing Performance Comparisons [2021] *spawn*

I too have problems with FPS games like CoD or BF due to being a veteran so I avoid games trying to be "real" (but actully being arcade).
One FPS (more mil-sim actually) I do kinda enjoy is ARMA (with 3rd person disabled servers)...the closest I have seen to "real shoting/damage implementation".

Hence I avoid games trying to be "realistic"..and go for games like CP2077 or Warhammer 40K...unless I am doing a mil-flight-sim.

Shooters on rails bore me to death...autoaim/assist is a pestilence...and I hate controllers with a vengance

 

They are more efficient on simple and single threaded wotkloads but these aren't a typical thing in GPU compute since you generally use it when you have a massive parallel workload. Thus this efficiency is more about graphics and less about compute where GCN may still end up being more efficient.

And it's 32 and 64 wide, not 16 and 32. I don't think there were any research on how WGPs compare to CUs when running old code but I'd expect them to be less efficient if only because the dCU mode isn't their native mode of operation. And in case of RVII vs 6900XT specifically memory bandwidth will play a huge role for RVII's advantage. Compute workloads don't do too well on IC.

 

CB updated their review with results with 21.7.1 driver

CB.de - F1 2021 im Test: Benchmarks in Full HD, WQHD sowie UHD, Frametimes und der Adrenalin 21.7.1 (Update)

 

Seems like a nice bit of extra perf. But only applicable to RDNA2. Makes you think why they couldn't get the developer to include the fix in the first place.

 

My guess is that most gains in RT workloads on RDNA2 are down to IC data management and devs won't do them since there is no IC anywhere but in RDNA2 PC GPUs. There's also no way for devs to do it through regular APIs either.

 

When I asked roughly around the RDNA2 launch timeframe, AMD said, there was no mechanism to explicitly manage the ∞$.

 

I'm sure that they can do this in drivers.

 

The gains aren't in RT workloads, the driver improves F1 2021 performance even more without RT.

 

For @JoeJ Frosbite next gen solution uses surfel and hardware raytracing acceleration. They will give a presentation at SIGGRAPH 2021

https://advances.realtimerendering.com/s2021/index.html

Surfel

 

Oh nice, it's a Lumen vs GIBS showdown.

 

Some notes gathered ...

Common:

Rebuilding your TLAS is virtually always a good idea.
Ray flags FORCE_OPAQUE, ACCEPT_FIRST_HIT_AND_END_SEARCH, and SKIP_PROCEDURAL_PRIMITIVES can help accelerate traversal of the acceleration structure.

AMD:

Ray flags involving traversal can change the traversal programs. Using these flags will allow the compiler to generate the optimal traversal program for the hardware.
General consensus is that building the acceleration structure is slow so use the build flag PREFER_ FAST_ TRACE as much as possible for both static and low deformation dynamic geometry. Avoid including high deformation dynamic geometry to the acceleration structure. Static geometry will give the best performance since you can build the highest quality acceleration structure and it never needs to be rebuilt or updated.
Avoid simultaneously tracing multiple ray query objects in the shaders.

NV:

Traversal is implied to be implemented as a state machine in the hardware. Using related ray flags will let the hardware change into a more optimal state for traversal.
Using the build flag ALLOW_COMPACTION is a hint for the driver to apply compression to the acceleration structures.

 

https://www.computerbase.de/2021-08/the-ascent-benchmark-test/

 

Performance drop is unreasonable. I wouldn't even consider enabling this, particularly on AMD on where no DLSS is available.

 

Didn't know where to post this, it's Nvidia Real-time Neural Radiance Caching for Path Tracing:

White paper:
https://d1qx31qr3h6wln.cloudfront.net/publications/paper_4.pdf

CUDA source code:
https://github.com/nvlabs/tiny-cuda-nn

 

I must admit to not understanding most of the words in that article, but with a 100x speed up, do we expect path tracing to become practical for modern games?

 

So in the end, they're trading bandwidth usage / memory access for tensors cores usage, right ? If tensors are not fully used even with DLSS, it make sense, even if I didn't understand everything

 

Wow the raytraced radiance caching techniques are coming out fast and furious.

Those fps numbers do look promising. Granted it’s on a 3090 using tensors so we won’t be seeing fully path traced games anytime soon. The paper doesn’t mention anything about dynamic BVH update cost and the test scenes are pretty small so these numbers probably aren’t representative of an actual game.

I don’t know if Quake 2 RTX already does importance sampling or any sort of irradiance caching but it’ll be interesting to see it updated with the latest techniques.

I understood it as trading tensor core usage for a lower number of rays and a less noisy image for the denoiser to deal with.

The point about avoiding trips to vram when training the network was an optimization of their DL training routine, not really reducing bandwidth usage compared to the baseline renderer. The actual performance savings comes from casting fewer rays overall.

 

https://www.computerbase.de/2021-08/f1-2021-raytracing-mittel-hoch-ultrahoch-test/