The highest resolution supported by the Benq MH684 is 1920 x 1200 (WUXGA). That's over seven times the resolution of a 640 x 480 (VGA) projector, which is the most common resolution supported by 13000:1 contrast ratio projectors that were launched around the same time as the MH684. 640 x 480 (VGA) is also supported by this projector.
A 1920 x 1200 (WUXGA) supported graphics resolutions is in fact the best supported resolution across all projectors of a similar spec and age to the MH684.
Across similar types of projector the worst supported resolution is 640 x 480 (VGA).