The NEC PA621 supports a maximum resolution of 4096 x 2160. That's over three times the resolution of a 1920 x 1200 (WUXGA) data projector, which is the most frequently found resolution supported by similar spec projectors that were released around the same time as the PA621. 1920 x 1200 (WUXGA) is also supported by this projector. This data projector also support graphics resolutions of 2048 x 1080 and 2560 x 1600 (WQXGA) and 640 x 480 (VGA).
A 4096 x 2160 graphics resolution is in fact the best supported resolution across all data projectors of this type and age.
A 640 x 480 (VGA) graphics resolution is the worst supported resolution across comparable types of projector.