I have a basic question: how do you know it when the vertical refresh is the problem and not, for example the horizontal refresh? I have an old computer that I have not dug into X windows configuration yet. I know it runs but the automatic settings didn't pick the right values. I just don't know where to start tinkering. I still need to read the X config docs so I have some idea what all those settings are in the config files. Alan On Monday 10 December 2001 11:01 am, you wrote: > Using Redhat 7.2 and finding it's pushing my Matrox G450 and monitor to > frequencies beyond the monitors capabilities. The specs list at 160Hz max. > I want the Vert. refresh to be set at 85Hz. > How can I force this setting?