Slow graphics performance in Gnome 3.14

[Michael Graham <oobermick@gmail.com>]

Hi all,

I've been trying to track down why games on my laptop have become
unplayable in the last few months and it seems to be an issue with
Gnome.  In older versions of Gnome I was able to play games no problem
but now the load in gnome-shell just shoots up.  Switching to a
simpler DM (I use blackbox) and the problem will go away.

For a simple example if I run glxgears in Gnome I see gnome-shell
switch from using <1% CPU in top to around 7-8% CPU (worse if I move
the window around).  If I do the same thing with a game running the
same thing happens only much worse.  I've tried the normal google
searches but nothing useful has come up, although I did read about
unredirecting which I don't know how to tell is happening or not.

Here's some info on my laptop if it's useful:

Intel(R) Core(TM) i7-4500U CPU @ 1.80GHz
Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 09)
NVIDIA Corporation GK107M [GeForce GT 750M]

(it's worth noting the issue happens regardless of which graphics card I use)

Any pointers will be greatly appreciated.

Thanks,
-- 
Michael Graham <oobermick@gmail.com>