Turbo mode is a feature in Scratch that runs projects much faster than normal by removing some artificial script delays. It can be activated by holding ⇧ Shift and clicking the green flag. This can be done again to deactivate it. Another way to turn on Turbo Mode is to See Inside a project, press Edit, then "Turn on Turbo Mode". This is the only way to turn on turbo mode on mobile devices.
Projects that might use turbo mode include, but are not limited to:
- Drawing projects
- Pen projects
- 3D rendering projects
Behaviour
Scratch runs every iteration of a loop for one frame. Turbo Mode allows the loops to run multiple times per frame, behaving like a 'Run Without Screen Refresh' custom block.[1] The result is that projects run much faster.
Problems
Turbo mode affects the whole project which may conflict with scripts that rely on the frame rate for timing. Animations for example may move faster than desired. One solution is to add wait blocks to slow the scripts down.
However, turbo mode is largely redundant[citation needed] due to the custom block "run without screen refresh" setting, which provides localised control over whether it should run without delay. Instead of enabling turbo mode, scripts that should run without delay can be placed under custom block definitions.
Detection
- Main article: Detecting Turbo Mode
Normally, switching the backdrop 10 times will take more than 0.1 seconds. When turbo mode is on, switching the backdrop 10 times will take less time. This can be used to detect if turbo mode is on.
when green flag clicked
reset timer
repeat (10)
switch backdrop to (please wait v)
end
if <(timer) > [0.1]> then
say [Please use Turbo Mode!]
else
switch backdrop to (Turbo mode detected! v)
