KDE stutter when switching or minimising windows (AMD GPU)

I recently got an AMD GPU to try to avoid visual stutter I was getting with Nvidia, but now I’m having some of the same problems with AMD. It makes me wonder if anyone has smooth visual performance on Linux.

I have a Ryzen 3700X, and AMD Fury Nano. My Nvidia card was a GTX 970. I’m using the mesa driver.

On GNOME, I was getting stutter which would drop several frames across the entire desktop about once a second. I only noticed this while running games, but it happened in every game I tried. The stutter was only present while the game was not running in full-screen, implying that the problem was GNOME’s compositor. If I changed window mode (between windowed and borderless-windowed) the stutter stopped for up to about 10 minutes. The problem was still present when I closed all my other running programs.

I am now in KDE to test whether it’s smoother than GNOME. I have been very happy with its performance in the game I tested it with, even while recording the game through OBS and with several other programs open. My PC can easily handle this set of tasks, raw performance is definitely not a problem.
However, I’ve noticed two severe problems with performance in KDE:

  1. When switching windows, minimising a window, or restoring a window, there is a noticeable short freeze, which seems to effect the entire desktop, and is visible in mangohud glxgears performance graph. It’s also visible on the ‘Show FPS’ KDE desktop effect.
  2. When enabling or disabling the Night Colour feature, the display stutters severely, dropping as low as 20fps, while the colour transitions.

Bear in mind this is on a fresh boot, running live from the installer USB. I haven’t noticed any other problems besides these, but there probably are some.
I’ve tried disabling all but one monitor, and a few other things, but they make no difference.

I prefer KDE over GNOME, so I’d rather use it, but at the moment both options have an unbearable source of stutter. I only switched to GNOME because of severe performance issues on KDE with the Nvidia GPU. Even before them, I had issues with XFCE too.

I had many other sources of stutter on GNOME as well, and though I was able to fix them, the causes either seemed nonsensical, or no-one else was talking about them.

I remember having stutter problems all the way back to when I was using Windows on a different motherboard, with a different CPU, and the Nvidia GPU; even the PSU was different. It seems like I’ve had similar problems across entirely different setups for years.

Is it normal to always get problems like this with Linux, or could something be wrong with my setup beneath the OS?