Quickly moving the mouse over anything that has a tooltip causes the FPS to drop significantly. Furthermore, doing it in menus makes the entire UI freeze for a short period of time. Watch the video for a demonstration: - YouTube
Geforce GTX 750
but with artifacts
asus-g75vw gtx660m 20gbram
In KDE, that issue occurs because OpenGL applications turn off compositing by default. You have to disable that from System Settings.
See more here: https://answers.unrealengine.com/questions/421227/strange-editor-behavior-in-linux.html
I know it is not a real solution for you guys but I really can’t recommend using Unity as DE for UE4. It makes the UE4Editor super slow and laggy. Personally I am using XFCE and have no problems with the issues from above. When I use UE4Editor on the Unity DE it gets quite slow.
It is a known issue that the smear effect appears when you don’t have a compositor but you can switch your compositor off to make things faster but be aware that it might cause “smear” effects like issue as @brothermechanic mentioned.
Thanks for your feedback.