You use the -v option to load a different display driver at startup. This option overrides the setting in 3dsmax.ini.
Follow the -v with one of these choices for the driver you want to use:
o: Loads the OpenGL driver.
d: Loads the Direct3D driver.
n: Loads a null driver.
For example, if you ordinarily run Nitrous using Direct3D 11 (the default display mode) and want to switch to Direct3D 9 for a session, you would type: 3dsmax −vx9