X-VESA enumerates all available VESA video modes, decodes the information returned by the VESA interface for each mode, and performs functional tests and measurements on the hardware resources actually accessible. It supports VBE specifications from version 1.0 to version 3.0, including non-standard versions and partial or defective implementations. X-VESA is designed for use on real hardware. Operation on emulators or virtual machines is technically possible but discouraged: timing, jitter and VRAM access speed measurements produce meaningless results in an emulated environment.