If you have a PC with nvidia card and mageia 4 KDE with propietary driver, you must check kwin cpu usage.
if you find that the CPU usage is high ( 40% or more ), these are the steps to solve the problem:
1 - As root open the file /etc/profile
2 - Add to the end of file:
export __GL_YIELD="USLEEP"
3- Save the file
4- Logout of KDE session
5- Restart X server
6- Login again
And vou will see a big drop in CPU usage of kwin, no screen tearing at all and of course this will greatly increase the performance and fluidity of Mageia 4