Hello!
I am using KiCad on Linux, and tried on my favourite distro (Manjaro) first, and then other distros and I have the same problem on all of them, the general slowness in EEschema, and PCBLayout. When I dragging the objects, or navigating through the design, it is really slow. Is there a good way to get rid of that.
My spec:
Acer 5620G notebook, with Intel T5550, and AMD Mobility Radeon HD2600.
Thanks!
Andrew
Comparing my laptop (Windows 8.1 / Core i5-4300u) and my pc (Kubuntu 15.04 / Core i3-3225) with the same recent Kicad build (5584) Eeschema is clearly running much faster on Linux. Moving a schematic chunk around looks instant on Linux and less so on Windows, even though my laptop is faster on all accounts.
In general usage of Pcbnew both seem very similar, with one notable exception: In Linux the 3D view feels just a tad lagging, the Windows view is perfectly smooth zooming or rotating.
Recent builds did a lot for the performance though, maybe you could try the PPA version.
I faced the exact same problem recently in pcbnew. Try switching the canvas mode to OpenGL, it has worked wonders for me (hit F11 in PCBnew or through the View menu).
Unfortunately I can’t seem to find anything similar just right now in EEschema though…
I’ve got Radeon HD 6370M. With open driver eeschema is very slow. It’s much better with fglrx driver.
I can’t use fglrx but I fixed this issue disabling “EXAPixmaps” in xorg.conf
Option "EXAPixmaps" "False"
see the bug report:
I had the same problem. I tried to install fglx driver but it made my GUI freeze at session (kubuntu/kde) opening 
Following your link I created the /etc/X11/xorg.conf.d/10-fixkicad.conf file, containing
Section “Device”
Identifier “radeon1”
Driver “radeon”
Option “EXAPixmaps” “off”
EndSection
It seems to solve the problem (that had been ruining my days for quite some time now).
Thanks 
currently eeschema does not have the OpenGL canvas - according to the cern targets it is on the list