problems running 375.66 with lightdm


I’ve been running a 3 gpu (570s - - - using 2 for graphics) 4 monitor setup (using nvidia drivers) since Feb 2012. Recently installed Debian buster (testing) and have since been having problems. 1 gpu would freeze up (mouse movement but no other inputs registering except alt-prtscn-b) and a reboot would clear things. That frequency of reboot increased (started at every few days and shrunk to a few times per day with the system running 24/7 (except in a power outage when I would try to shut down the system before the ups died)). I was thinking that it might be a hardware issue until I found (at one of those reboots) that my network files had also been corrupted. That necessitated a reinstall. Did that - - - found that everything works quite well on nouveau except I haven’t been able to setup my desired 4 monitors into one virtual screen. My working mode needs to have at least 3 monitors (1 in portrait for text/pdfs on the left and 2 more in portrait used for files (use quite a few vms for single functions and work in between) the fourth (also in portrait and above the center of the bottom three) is not as necessary but is still useful. Have thought of having 2 more monitors so that I could have 2 for text/pdfs and the other four for work but with the issues and holding off on that addition.

Would love to give you log files but they disappear in a reinstall.

Should I be moving to a newer driver?
(IIRC 352.xx worked for a l-o-n-g time)
Is it lightdm that’s the issue?
(Have also been running that for about 3 years.)