Ubuntu 18.04 video stutters every second regularly with nvidia GPU

I figured it out but I'm not entirely sure why this works!

It turned out that I had one of my gnome shell extensions (SystemMonitor) update values every second, and as soon as I turned this off it no longer had a stuttering issue. Why exactly that was the problem I am unsure, but turning it off fixed it.

Just to add to the list of solutions:

TLDR: Uninstall "System Load Indicator" if it's installed.

I'm on a freshly installed version of PopOS 20.10 (Ubuntu-based), a GeForce GT 710 GPU. Found this example which clearly showed that my video was stuttering regularly every second (https://codepen.io/0x04/pen/FHjnd). I thought it was the NVidia driver, so I switched to Nouveau, but the issue persisted. I then compared this to the animations on the recovery install that PopOS includes, which was smooth as silk. So I came to the conclusion that I had installed something, which was the cause. Turns out I had installed a utility called "System Load Indicator" which regularly samples CPU/GPU/RAM usage. Stopping that utility fixed everything.