I built my PC back in 2019. I am still using the same CPU : i7 8700k. I have upgraded my GPU to an rtx 3070. I play only GPU heavy games in 4k usually with DLSS. I’m able to run most games in an acceptable framerate, 50-60fps. I would say my frame times could be better tho. I dont run any CPU heavy applications, but i have noticed that with these latest AAA games it takes forever to compile the shaders. My CPU is pretty outdated at this point, and I’m wondering if it would even be worth upgrading considering my use case and that I am mostly happy with my gaming performance. Oh and I run Linux if that makes a difference.
I use mangohud overlay and while I don’t track each CPU core, I track the overall percentage and it hardly over 60% while gaming.
That means your CPU should be just fine, though single thread performance could still be an issue.
If the overlay can’t show you all the cores separately, you would need to alt+tab to check the proper CPU graph from time to time. If single thread performance is a bottle neck, you should see a single core staying at 100% for a long period of time or multiple cores taking turns to briefly visit 100% load.