Mesa 7i76 time out error

In any case the WD bite is the key (all the sserial errors are a red herring)

(So I should have asked for a dmesg printout first thing)

Errors after a hour or so point to thermal management

I suspect a PC latency problem instead of possible 6I25 card issues
since you would expect instant following errors if PCIE card access failed

ok.

I ran the machine the whole night, and machinne is still running.

here is a recent kern.log file:

Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768172]
Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768175] In recent history there were
Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768177] 4198128, 4215840, 341832, 4198536, and 4200816
Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768179] elapsed clocks between calls to the motion controller.
Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768190] This time, there were 3865080 which is so anomalously
Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768192] large that it probably signifies a problem with your
Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768193] realtime configuration. For the rest of this run of
Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768195] LinuxCNC, this message will be suppressed.
Nov 2 04:51:36 linuxcnc-desktop kernel: [21631.768197]

I de-activated the screensaver and log screen now, as it seems to have some issues on this pc.

but what is different this time, the machine has been running whole night, no errors. I'm happy about this, but I'm not sure what I have done different.