Customize performance and display of your Doom^3 with this lightest tier fix, based upon the rule of overriding the default game configuration with possibilities standing up to modern expectations, making the best of the excellent iDtech4 engine, still kicking!
Simply, put an extracted "autoexec.CFG" into your "Doom3/base" folder - or any mod folder of choice - then open up the file and follow written instructions present there. Mind the only thing unaffected by commands of "autoexec" is the main menu of the game started. This is the "config" way of bringing the vanilla game stand up to modern expectations. The "autoexec" file overrides the basic "config" file, therefore anything defined in the "autoexec", will be permanent setup, ranging beyond what the common Doom^3 menu establishes.