Mode timings can be derived from the information in XFree86's doc subdirectory. However, it is no longer required to specify such timings in an XF86Config's ``Monitor'' section(s), if only standard mode timings are to be used. The server automatically inserts VESA standard mode timings in every ``Monitor'' section, and these modes will be checked first for mode constraints (monitor sync tolerances, video memory size, etc.).
Furthermore, it is also no longer required to specify mode names in ``Display'' subsections. Should no mode names be specified (or those specified do not yield a usable mode), the server will automatically select as a default resolution the largest usable mode, whether or not the chosen mode is specified in the corresponding ``Monitor'' section.
For a CRT monitor, you should still specify horizontal sync and vertical refresh rates in the corresponding ``Monitor'' section. Otherwise, the server will default these to those of a VGA monitor, which will limit resolutions to not much more than 640x480 at 72 Hz. For a digital flat panel, any sync tolerances should be removed from the corresponding ``Monitor'' section. The driver will automatically calculate these from the mode that is active on server entry. The driver also inserts timings for a mode called "Native panel mode" that represents the panel's native resolution.