System Options > Performance

Regenerate model automatically
When this checkbox is enabled, the 3D model will be regenerated automatically in case of parameters change (upon exiting the variables editor, changing construction line positions, etc.). If the checkbox is disabled, then the automatic regeneration does not occur in such cases. In such case, you can only regenerate the model manually.

Use multithreading on calculations
This checkbox activates the mechanism of multithreaded calculations inside the system on computers having multi-core processors or on multiprocessor systems. This enables to increase the speed of regenerating the models. Multi-threaded data handling is used upon calculating geometry of 3D operations, calculating finite-element meshes.

Undo/Redo buffers
You can specify the maximum number of user actions to be remembered by the Undo and Redo commands. This parameter should be specified before opening a file.

Don’t display 2D objects smaller than, pixels
Objects, which size is smaller than the specified value, will not be displayed on the drawing. This option helps to speed up manipulations with the large drawings.

Maximum size of image for raster projection, pixels
The maximum image dimension for raster projections does not exceed the specified value. The aspect ratio of the image is preserved.

Show regeneration time
The parameter allows to display information about the recalculation time to the status bar.