Is it bottle neck in X or the kernel?

[Kishore]

My question here is: Is it X or is it the kernel that is the weak link that 
sometimes make the FR painfully slow to operate?

I now have qtextended 4.4.1 installed with the 4.3.2 release's kernel and the 
UI is really fast! When i first flashed 4.4.1 rootfs, i still had the kernel 
from FDOM and while the UI was first on first boot it became slow over time. 
FDOM was slow from the start.

Debian with XFCE OTOH was pretty fast and the change in kernel for qtextended 
made significant difference so i am thinking the slowness is likely kernel 
related.

Now with qtextended i still have a somewhat flaky audio playback. I have not 
tried video!

I would appreciate anyone throwing more light on the issue.
-- 
Cheers!
Kishore