Mac randomly segfaulting and logging out

For the past six months or so I've been having an issue where I'll be working on my Mac Pro (details below) and I'll do something (click a button, close a window, copy some text- it's not consistent) and the Mac will freeze for a few seconds and then I'll be logged out (immediately taken back to the login screen). I can then log back in and most of the apps that I had running when I was logged out will be running, although I'll need to restart a few of them. These events will often occur in clusters- I won't have an issue for a week or so, and then it will happen multiple times over a day or two, and then will stop occurring for another week or more. In the last few days it's happened about five times. I always check the system.log and there doesn't seem to be anything of interest preceding the logout, and when it happens I always get the following lines:

Mar 31 11:41:40 BradsMacPro com.apple.xpc.launchd[1] (com.apple.WindowServer[260]): Service exited due to signal: Segmentation fault: 11 sent by exc handler[0]

Mar 31 11:41:40 BradsMacPro sessionlogoutd[39398]: DEAD_PROCESS: 117 console

Sometimes these lines are in reverse order. Other than those two lines, there doesn't appear to be anything consistent in the logs after the sessionlogoutd lines. I can provide more complete system.log lines for each of the events that have occurred if that would be help. I also save all of the WindowServer DiagnosticReports- here is the one from the most recent logout:

https://pastebin.com/UeU9EzrF

I also ran EtreCheck, although it didn't find anything that seemed relevant:

https://pastebin.com/pPbzh5T4

I don't know if it's related, but in the DiagnosticReports folder I also have a number of WindowServer files for wakeups_resource which occur during the same periods of time when I'm having the logout issues. These reports have a line like this in them:

Wakeups: 45001 wakeups over the last 206 seconds (218 wakeups per second average), exceeding limit of 150 wakeups per second over 300 seconds

Here is a complete wakeups_resource file:

https://pastebin.com/AXLn0ZG3

I've searched around to try and find a solution and here are some similar reports of people having issues like this:

https://discussions.apple.com/thread/6850739

https://apple.stackexchange.com/questions/314657/macos-freezes-for-a-few-seconds -then-logout

https://apple.stackexchange.com/questions/188255/yosemite-regularly-crashes-retu rns-to-login-screen

Hardware setup:

Mac Pro (Mid 2010)

Mac Pro Model: MacPro5,1

2 2.4 GHz Quad-Core Intel Xeon (Xeon(R)) CPU: 8-core

32GB RAM

macOS 10.3.3

Video Information (two cards driving three monitors):

• ATI Radeon HD 5770 - VRAM: 1 GB
  • MPCP28UHD 2560 x 1440 @ 59 Hz
  • DELL 2001FP 1200 x 1600 @ 60 Hz
• NVIDIA GeForce GT 120 - VRAM: 512 MB

  DELL U2412M 1200 x 1920

Other than these logout issues, the Mac seems to be running very well. Any help or suggestions would be appreciated.