It will run at any resolution, if you use a autoexec file.
In your doom 3/base folder, create a text file named "autexec.cfg"
Put this text in it:
Code:
seta r_mode -1
seta r_aspectratio 2
seta r_customHeight 1200 //change this to match your height
seta r_customWidth 1920 //change this to match your width
seta r_fullscreen 1
Then when you start up, it will load that resolution - the in-game menus won't display non-standard values so you'll have to start a game to see it is working correctly.