High Sierra freezes every few seconds, for a few seconds

Hello!

My High Sierra Hackintosh has been having this problem since I installed it using this guide. Every few seconds it will freeze for a moment or two and then carry on normally. Sometimes this will occur when I open an app or simply right-click on something simple, like the Settings icon to show the context menu.

I prevented it from using APFS, if that is relevant. I also checked and Spotlight is not indexing (I went for a fresh install a couple weeks ago, so there’s not much saved on it to begin with).

Any idea as to what could be going on? Thanks!