Changing monitor refresh rate after install

[John Nilsson]

On Sun, 2005-07-24 at 11:15 -0500, BBBB wrote:
> It seems that I installed my monitor with only the 60hz refresh rate
> available. Is there a way to make more rates avilable?

If you have a reasonably new monitor, and a standard D-SUB cable to
connect it with, X should be able to handle it automatically via DDC. In
this case it is possible that you only get 60Hz because you let X select
the highest possible resolution, try lowering it then.

If you have a non-standard setup you might be forced to do some manual
configuration. Edit /etc/X11/xorg.conf to do that.

What you want to change is the HorizSync and VertRefresh values in the
Monitor section. Here is an example from my setup.

Section "Monitor"
        Identifier   "SyncMaster 975p"
        VendorName   "SAMSUNG"
        ModelName    "SyncMaster 975p"
        HorizSync    30-96
        VertRefresh  50-160
        DisplaySize  361 271
        Option       "DPMS"
EndSection

Be cardule to get the correct valuse, it is possible to destroy your
monitor by entering to small/large values for your monitor. You'll most
likley find correct values in the tech spec of your monitor model from
the manufacturers website (or in the manual if you have one).

> Also, is there any advantage to specifying a specific monitor model rather
> than "Generic Monitor"?

If X can't detect this stuff via DDC it will assume that you have a
rather low performing monitor just to be on the safe side.

-John