Works like a charm on my Fedora 21 and HP Latitude E6400.
I’ve been using my trustworthy thinkpad for a couple of years now, but as soon as I installed Fedora on it, it became quite slow due to gnome-shell using a huge amount of CPU power.
My thinkpad isn’t the quickest out there, it’s a dual core machine from around 2006, but 50% CPU on two cores for just Gnome was a bit excessive.
I’ve been searching a lot, and didn’t found any solution, until I started fiddling with Gnome-tweak-tool and saw the “Background logo” entry.
If you haven’t yet; Install gnome-tweak-tool with the following command:
sudo yum install gnome-tweak-tool
The background logo is an PNG overlay on your desktop, and that overlay doesn’t work well with Intel GM cards.
Start gnome-tweak-tool, disable that extention and see your CPU usage drop to 2%, which is what it should be.