So, I changed my daily driver to linux several months ago and my gf a few weeks ago. I noticed 2 strange but good things after the change. For my system I have a onboard sound card (stereo) and am using 3 of the 5 speakers for my decade or so old Creative labs 5.1 speakers. Under win 10 most of my sound came from the left and centre speakers with base cannon doing its thing, under linux using the generic drivers included during install all 3 desktop speakers put out the appropriate sound. YAY!
My gf is using my old hand me down prebuilt. Under win 10 the fans on that thing would be kicking on and off constantly, I could hear the fans over the running water doing dishes. Now? 99% of the time is straight silence unless she is playing ESO.
Only issue left on her machine is having it be able to play ESO and be able to watch a yt vid at the same time. Right now it is ESO and nothing else, when she tries the whole system lags until she can move the mouse painfully slowly to the browsers X. forget which intel cpu is in there(it’s about 8-10 yrs old iirc), GTX 1060 6 3gb, and 16gb ram, Kubuntu 24.04, KDE. Are we asking too much of the system, did I misconfigure something? She was able to do this on windows


You said this happens during Elder Scrolls Online, right? Maybe have her close the game’s launcher while the game is running. In my case, I noticed jittery performance in everything, including moving the cursor, until I closed the launcher. May or may not be the issue, but it does sound similar to what happens to me when I leave that game’s launcher open.
She does close it as even on windows she found it made the system laggy, and it appears hardware acceleration is on in firefox but I think the snap is installed (thought I installed the flatpak same install on my system), every setting is the same as mine.
Damn, I really wish I could offer more help beyond ensuring drivers are set up correctly for NVIDIA. I mean, you could also check the power profile too, using something like cpupower-gui to see if it’s in power saving mode. I suppose you could also close other applications to see if one of them is interfering, since you said Firefox may have something to do with it. I suppose it’s possible Snap has something to do with it too.