Question Best way to profile GPU usage?

So how do I go about profiling the actual GPU usage (not frame time) of individual components of my game?
The best measure I have of how much of my GPU is my game using is MSI Afterburner (which actually gives me the total system usage, which includes anything I have open right now on the machine), but at the same time it can give me reasonable guesses on what uses a ton of GPU if I watch the graph and toggle stuff on and off.
The issue is that I get at best some vague 'this seems to be about 8~12% usage' which is not really all that helpful besides comparing to other components, but that can't really be used to compare "Component A version 1 with Component A version 2" since the differences are bound to be very minimal. It is also very unreliable as stuff will start using the GPU randomly and I need to measure the bumps many times over to get any semblance of accuracy.

The "CPU Usage/Rendering" seems to be completely useless for that, since it likely only gets me how much the CPU spent dispatching stuff to the GPU, and I can't figure out what the "GPU Usage" graph even means, since a clear 10% GPU usage shows in the graph as a conversion of Shadow/Depth to Opaque usage and a very minor total reduction on the GPU usage.



One way to test it might be disabling the frame rate limits and let it rip on my GPU and measure the max frame rate I can get, but my 2014 laptop tends to restart if I let the GPU usage go over 80% for longer than 2 minutes. So that's not an option for me.

TLDR: How to accurately measure individual components of my game for Frame Time and GPU Usage? I want to lower both of those but I am not sure they are perfectly 1-1 equivalents.

 

Hiya, what pipeline are you using, and what is the target hardware? Also how exactly is the grass made and rendered? It looks to me it could be both a CPU and GPU hit. Hard to tell because draw calls are a CPU hit as those are main thread stalls but show up as GPU. Then there's the GPU side like vertex pressure, shader used etc.

A depth prepass is a very fast render of objects to prevent overdraw, but it is bad on mobile (tile deferred hardware). I would advise watching www.youtube.com/watch?v=wavnKZNSYqU to get a better understanding of vegetation on desktop or console hardware.

In addition there's https://unity.com/how-to/10-tips-optimizing-console-game-graphics which goes into vegetation optimisations.

The TLDR is:

• no tessellation
• use depth prepass with cutout
• recycle your grass objects (use less of them)

 

Well, the question for this thread is more of a overall generic question. I have many things that I need to optimize and the grass is simply the one that is most likely to be the biggest culprit, hence why it was used as an example of what I am doing right now.

The target platform is PC, the version is 2020.3.f14 and the render pipeline is the built in render pipeline.

OBS: The grass is the exact same 4 triangle mesh being rendered a ton of times through instancing and being animated/converted into flowers/bent and cut in the instancing setup() + vertex shader