Along other PC's , I own 3 Thinkpad T42 laptops with Radeon HD 9600 and 9800 (RV350), that according to today standard are obsolete products, but unfortunately I sometime use them, as each of them have an assigned rarely used task.
The main issue after upgrading from 16.04 to 18.04 through 17.10 is that on this desktops the scroll bars on all Mate apps works extremely slow out of the box after upgrade. So scrolling par example through Notepadqq or Mozilla Firefox looks at least 20 times faster. So I go to Mate tweek and change compositor from Marco default software one to Marco GPU to get them at list more faster but also extremely slower by comparative with Notepadqq or Mozilla, or how it works in 16.04
I note that on Mate 16.04 this scrolling was extremely fast. The slowest scrolling I noticed first in Control Center, but Mate terminal is neither faster on all this laptops.
I think that some code was removed from Marco compositor or ... that made the mate desktop scrolling extremely slow, or is an issue with with some window scrolling / content acceleration that was changed in Marco.
I also hope that someone will update mate desktop on 18.04 to fix this slow content scrolling "acceleration" and come with an update in next months. Other apps like Mozilla Firefox can scroll content extremely fast on this desktop by comparing with scrolling of Mate Terminal, so Mate developer should fix this ... as it works on 16.04 OK, it should work also in 18.04. As other apps work OK, also Mate / Mate desktop ones should work OK, and not stay behind saying "we drop further 32bit support"
Thank you all for all this grate work on this grate desktop.