The highest resolution supported by the Acer U5313 is 1920 x 1200 (WUXGA). That's over seven times the resolution of the most frequently found graphics resolution of 640 x 480 (VGA). In addition, this Acer projector supports a graphics resolution of 1280 x 800 (WXGA).
A 1920 x 1200 (WUXGA) graphics resolution is actually the best supported resolution across all projectors of this type and age.
A 640 x 480 (VGA) graphics resolution is the worst supported resolution amongst similar types of multimedia projector.