Hello!
I came across this article on Phoronix http://www.phoronix.com/scan.php?page=article&item=ubuntu_1210beta_desktops&num=1 about OpenGL performance across different desktops. The verdict is ...KDE 4.9 being the fastest Linux desktop when having KWin automatically suspend its effects on full-screen windows. This comparison is done on Ubuntu but results shouldn't be much different on Mageia.
This option is not enabled by default in Mageia 2, and I think it would be a good idea to have it enabled by default in Mageia 3. While it's easy to change that option in KDE System Settings, many users won't know about it.
What do you think?