Hi Fred,
As I understand it, if your system and your video card can use the "openGL, GLX", then you can enjoy faster and much better video performance including desktop special effects, 3D effects, for gaming, etc... I provided a links below. Of course you must have the correct video drivers installed to be able to use this "video rendering" system. From what I have read, it is best to use the video card manufacturer's proprietary drivers for your current Linux System, if they have them.
Some video cards are so old (like mine), that you cannot even use this in the newer operating systems with GLX. Some people have had to stick with older versions of Linux Mint, like version 13 Maya, to take advantage of this "openGL", or upgrade their video card and other hardware, or find some type of workaround.
I have been able to use my Linux Mint 17.1 KDE and Kali Linux pretty well even without being able to load the "openGL", GLX, drivers. Of course I wish I had newer and better computer hardware to be able to do everything I would like to do and to utilize all the very cool special effects features of the various Linux operating systems including those Linux Mint offer.
GLX - Wiki information
https://en.wikipedia.org/wiki/GLX
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X.org-Edgers PPA
you can also add the X.org-Edgers PPA if you’re concerned about your graphics performance. This PPA will give you the absolute latest version of the X.org X display server, which is a part of the entire graphics stack. If you want better graphics performance, it’s important to keep the entire stack updated.
You shouldn’t use this PPA if you use the proprietary graphics drivers.
Type in at the console terminal prompt each line one by one, or copy and paste each line:
sudo add-apt-repository ppa:xorg-edgers/ppa
sudo apt-get update
Oibaf is a PPA that includes the very latest graphics drivers, and is updated virtually every day. This PPA is only helpful if you’re using the open source drivers rather than the proprietary nVidia or AMD drivers – proprietary drivers are not included.
Type in at the console terminal prompt each line one by one, or copy and paste each line:
sudo add-apt-repository ppa:oibaf/graphics-drivers
sudo apt-get update
FYI: Best 7 Ubuntu PPAs to add to your Linux installation
http://www.makeuseof.com/tag/top-7-ppas ... d-systems/
Hope this helps...