When i make a simple trial in builder with only a TextStim that should display from frame 60 to frame 120 (framerate of monitor is 60Hz) and nothing else it is not displayed if i run the trial from builder, I only see a grey screen. If I change "routineTimer.add(2.000000)" to "routineTimer.add(10.000000)" (in the "lastrun.py" ) and nothing else and run the trial I see a grey screen for approximately 4s and the text of the TextStim for 4s, which to me indicates that the framerate is much slower than 60Hz.
I ran the demo "timeByFrames.py" and got a mean of 72.9ms and an SD of 0.28 and zero dropped frames. So my framerate is stabile around 1/0.0729s=13.7Hz
Do you have any sugestions? Is it a driver issue?