There is no unit of measurement for the simulation flow. The simulation is running in steps.
You can increase and decrease the time between two steps in the dialog "Options/Global Settings".
The time between two steps (value * 40ms) is not guaranteed.
To increase CPU usage to 100%, set this value to 1.
The signals of all devices are calcutated and displayed for each simulation step.
All devices except input- and output-devices of sub curcuits have a tunable delay.
A delay of 1, the default value, means that all incoming signals will change the output value
after one simulation step.
Be aware of undefined results in backtraced circuits if you use oscillators with a switch-time lesser than the sum over all delays.
To turn off all delay effects you can increase the bust value in the dialog "Options/Global Settings".
Then each device will be calculated n times in one simulation step.
use the ´s´-key in the main window to perform single simulation steps.
The calculation of all devices is running permanently.