How often should I save a drawing file. AutoCAD AutoSave.

    My answer to the question how often
should I save is only save the work you don’t want to do again! You will lose
work and you will have to redo it! Always save when you get up from your chair,
take a break etc. As soon as you feel you accomplished something, save. Of
course long save times will make your saving a more strategic event. No one
wants to spend 10 minutes 3 times an hour saving.

    AutoCAD AutoSave time is set in Options > Open and Save> Automatic save. 

This does not save the current file it only makes a copy

of the file with the .SV$ extension. The .SV$ can be renamed to dwg and used in
an emergency. This does not work with Plant3d. The file would have to be
deleted and re-imported into the project.
    I like to set the AutoSAVE time as a reminder to save. I set
the AutoSave to ~20-30 minutes.
    I try to get to the point where I don't see the AutoSAVE
happening at ~20-30 min in the command line. Then I know I am saving enough. If
you see the AutoSAVE you need to save because you have not saved in ~20-30
minutes.
    If the AutoSave takes a long time you don't want it to AutoSave
because then you have to save again. You might set the AutoSAVE time higher.
    If you see the AutoSAVE you need to save because you have
not saved in 30 minutes.