For testing I tried to run Path of Exile and Guild Wars 2 on Ubuntu Budgie and Mint XFCE. To run PoE I used steam. To run GW2 I used Lutris.
When any game is fully loaded and I do not touch anithing all works fine. But when I start move character or camera fps drops to 4-5 and my HDD becomes crazy. I.e. GW2 process owerall hdd i/o is 35MB/s everytime when I just stand in town. In PoE same situation. I tried to use SSD and problem becomes less fatal but anyway
spikes didn't disappear.
The problem persists for all heavy games not only this two.
i5 - 6600
2x1Tb SATA HDD
256Gb SATA SSD