Stuttering in Games

Current build: Ryzen 3600, MSI B450 Gaming Max, RTX 2070 Super, 4 x 8 DDR 3200 Ram, TX650 PSU

Ever since I rebuilt my PC last year I've been having an issue with stuttering. Once per minute or so the game will freeze for a fraction of a second (but is very noticeable/problematic in some games like beat saber or MOBAS). This issue doesn't seem to be tied to GPU usage as it does it in lighter games like Heroes of the Storm and isn't affected if I lower the settings in games. Initially I chalked it up to a bad motherboard as it was having all sorts of other issues. However, while those issues were resolved with a replacement mobo, this one has persisted.

Other than replacing the mobo, I have tried:

Running it with only 2 of the 4 sticks of Ram (tried with each pair)

Using my old 1070

Re-installing GPU drivers with a clean install (used DDU to uninstall)

Updating the mobo bios

At this point, my best guess is that it's either my CPU or possibly (but less likely my aging PSU).

I only really suspect the PSU because it is fairly old at this point (about ~7 years old), but it should have enough power

The reason I suspect the CPU is that if I try any sort of overclock, including setting it to 'gaming mode' in the BIOS the CPU becomes unstable and will not even boot.

I also have a less frustrating and possibly related issue with artifacting when my PC turns on or switches inputs I posted about here that I still have resolved.

I'm trying to figure out how to diagnose the issues and what tools I could use to do so. The CPU is still under warranty so I could potentially RMA it, although that might put my down my PC for a month or two if AMD doesn't send me a new one first.

Link to userbenchmark. For some reason it states there is a high background CPU usage, but when I pull up task manager it's only at 2% (as opposed to the claimed 18%)