The highest resolution supported by the NEC PA522 is 4096 x 2160. That's over four times the resolution of a 1600 x 1200 (UXGA) data projector, which is the most common resolution supported by projectors of this type and age. This projector also support graphics resolutions of 2048 x 1080, 1920 x 1200 (WUXGA) and 2560 x 1600 (WQXGA) and 640 x 480 (VGA).
A 4096 x 2160 graphics resolution is in fact the best supported resolution amongst all comparable spec projectors that were released around the same time as the PA522.
A 640 x 400 graphics resolution is the worst supported resolution amongst comparable types of projector.