

Just start listening to dubstep and you’ll stop noticing 😆.
Maybe run lm-sensors and make sure the CPU/GPU isn’t being thermothrottled? I’d usually look at dmesg and look for red stuff. Any hardware issues are usually pretty obvious.
Try other apps. If you youtube or VLC behaves the same, the problem may be outside of jellyfin. If not, it narrows it down.
If could even be the server not being able to transcode in realtime. Try watching a file known to already be in a suitable format. It should direct stream and be much less load on the server. I’ve seen server encode CPU saturation and it does kinda look the same as client decode stutter. If it’s the server, you’ll probably see the same stutter from another device such as a phone.
Ahh. That’s usually among the red stuff in dmesg. I glad to hear you solved it, but a failing hard drive is a pricey thing to endure these days.