B550
I'll start with a PSU upgrade for safety, then the new CPU will be ready and perform better.
If you're considering an upgrade, this seems like a solid choice. For higher performance, an A-tier 750W or more would be ideal.
Are you keeping your games on the hard drive? This seems to be the main problem, not the processor.
Considering an 850mm 2021 Corsair review, comparing AIO versus big tower coolers is a common choice.
It's stored on a solid-state drive but contains just a few F1 titles and another one