How to determine bottleneck in a game with HWiNFO and RivaTuner

[EchoReaper]

I want to learn how to identify bottlenecks in games using HWiNFO and RivaTuner. I already know how to use the two programs to get data, but not what data I should be looking at, and what it means.

For instance, I loaded up Astroneer and was getting stuttering every few seconds as I walked. The stats I was tracking with HWiNFO and RivaTuner didn't show anything amiss:

CPU usage was not near 100% on any core, GPU utilization is at 100% which AFAIK is a good thing, and my HDD read rate is negligible so it's not an issue of loading textures from a slow disk. It seems I'm either looking at the wrong stats, or some usage spikes while the game is frozen for a split second and immediately returns to normal when it recovers.

How can I find out what's causing the issue? I'm not so much interested in the exact cause, but how I can use these two tools to discover the cause. My main goal is to learn how to identify bottlenecks.

 

[kanewolf]

GPU utilization at 100% means that you are being limited by the your GPU. That might be OK or it might be why you are stuttering. ANY time you have 100% utilization, that is a limitation of some kind. It might be OK if you have 300FPS because more work being added to the GPU will only slow the FPS to 150.

 

[EchoReaper]

GPU utilization at 100% means that you are being limited by the your GPU. That might be OK or it might be why you are stuttering. ANY time you have 100% utilization, that is a limitation of some kind. It might be OK if you have 300FPS because more work being added to the GPU will only slow the FPS to 150.

Oh, alright. Further investigating the GPU, is it normal for GPU clock and utilization to fluctuate? For instance, here's a screenshot of some graphs from during Total War: Attila @ 20 fps: