[1][2] In contrast, fixed frequency monitors can only synchronise with a specific set of scan rates.
At this point, PC and Mac owners with multiple graphics cards required unique monitors for each of them,[6] and by the late 80s all of the below computer video standards required monitors which supported a small number of specific frequencies: After 1987's VGA.
In response, VESA established a standardized list of display resolutions, refresh rates, and accompanying timing for hardware manufacturers.
Most modern multiscan computer monitors have a minimum horizontal scan frequency of 31 kHz.
[11] In both multisync and fixed-sync monitors, timing is important to prevent image distortion and even damage to components.
[12] Most modern multiscan monitors are microprocessor controlled[13] and will refuse to attempt to synchronise to an unsupported scan rate, which usually protects them from damage.
In recent years, LCD monitors designed for gaming have appeared on the market offering vertical scan rates of 120 Hz and up.