Ok, just another annoying issue on Ubuntu Mate 18.04 make me investigate and found an easy fix, that might help others in this forum.
On Firefox I have a really annoying screen tear when scrolling, after Firefox introduce "Smooth Scrolling" couple of releases before. An I observe the same thing in Youtube video playback, and couple of days ago It start to ... me and ask myself where is the problem?
The video card is Quadro 2000 is old, not very performance for this days, but is not ... , and what the hack is a simple Youtube playback, or text scrolling in Firefox, for a video card that you can do professional CAD work for low-medium assemblies.
So with this learn myself what a screen tear means, vsync, g-sync, free sync,.. install and test Chromium, check in Windows...until I open another one of my system with a worse card, a Quadro FX580 (witch I intend to replace) and somehow found that it work smoothly (same Ubuntu Mate), and said what the hack, how is this possible, older generation, and low entry video card work better ...
OK - SO THE SOLUTION
Control Center -> MATE Tweak -> Windows and select "Marco (Compton GPU Compositor)" instead of Marco (Adaptive Compositor)" to solve this ... so happy playing...
I don't remember this issue on 16.04, and I just notice it with that smooth scrolling in Firefox witch is not for a long time introduced, so maybe this issue is present only on 18.04, I don't know, I just investigate this in last 2-3 days, as this issue it get stuck in my eyes