Comment # 127 on bug 1112824 from Dead Mozay

(In reply to Wolfgang Rosenauer from comment #126)
> I've lost track about this issue during the last weeks but I'm still facing
> Gnome performance which is really hard to work with on my laptop also with
> latest TW snapshot.
> 
> I'm supposed to run Gnome under Xorg. At least that is what my session
> selector says but on the other hand when I look at the process list I see
> Xwayland running and not Xorg. (Looks like a bug to me)
> 
> My system is a Core-i7-7500 (Quad) but the Gnome shell performance is really
> hard to work with. All window/desktop actions (moving windows, switches
> workspaces etc) are quite laggy and not smooth at all. This started in
> October and only got better a bit. Compared to before it's really slow.
> Considering switching to Xfce or something for the hope it'll be better.

echo $XDG_SESSION_TYPE will show what session you have X11 or Wayland.
To activate the X11 session, you need to edit the file /etc/gdm/custom.conf,
remove comment from the line WaylandEnable=false and restart session.