Thanks so much for your help and pointing me to this article!
I have kept the 3rd party drivers as you noted that they are unlikely to be worse.
I did add PsychTweak(‘GetSecsClock’, 1); to the beginning of my script and now I am getting the following warning that the flip command seems to be missing:
INFO: PTB’s Screen(‘Flip’, 10) command seems to have missed the requested stimulus presentation deadline
INFO: a total of 19 times out of a total of 209 flips during this session.
INFO: This number is fairly accurate (and indicative of real timing problems in your own code or your system)
INFO: if you provided requested stimulus onset times with the ‘when’ argument of Screen(‘Flip’, window [, when]);
INFO: If you called Screen(‘Flip’, window); without the ‘when’ argument, this count is more of a ‘‘mild’’ indicator
INFO: of timing behaviour than a hard reliable measurement. Large numbers may indicate problems and should at least
INFO: deserve your closer attention. Cfe. ‘help SyncTrouble’, the FAQ section at www.psychtoolbox.org and the
INFO: examples in the PDF presentation in PsychDocumentation/Psychtoolbox3-Slides.pdf for more info and timing tips.
INFO: This number is fairly accurate (and indicative of real timing problems in your own code or your system)
INFO: if you provided requested stimulus onset times with the ‘when’ argument of Screen(‘Flip’, window [, when]);
INFO: If you called Screen(‘Flip’, window); without the ‘when’ argument, this count is more of a ‘‘mild’’ indicator
INFO: of timing behaviour than a hard reliable measurement. Large numbers may indicate problems and should at least
INFO: deserve your closer attention. Cfe. ‘help SyncTrouble’, the FAQ section at www.psychtoolbox.org and the
INFO: examples in the PDF presentation in PsychDocumentation/Psychtoolbox3-Slides.pdf for more info and timing tips.
However, when I comment out the PsychTweak function after closing and opening a new PTB - matlab session (I presume now using the default real clock), I do not get the same error when I close the screen after running 100 test trials. And the flip time before current time does not seem to come consistently.
I do always input a tWhen in my screen flip command and the duration is short - usually less than 1s.
I did try to look into my clock sync status:
visstim@VisStim01:~$ timedatectl timesync-status
Server: 185.125.190.57 (ntp.ubuntu.com)
Poll interval: 34min 8s (min: 32s; max 34min 8s)
Leap: normal
Version: 4
Stratum: 2
Reference: B7A08584
Precision: 1us (-25)
Root distance: 800us (max: 5s)
Offset: +431us
Delay: 235.180ms
Jitter: 134.048ms
Packet count: 119
Frequency: -14.143ppm
I am not sure if one of the other clocks would work better?
Thanks for your help, I really appreciate it!