[NBLUG/talk] Refresh Rates (was monitor resolution question)

[Justin Thiessen]

On Sun, 24 Aug 2003, E Frank Ball wrote:

> On Sun, Aug 24, 2003 at 02:47:56AM -0700, Justin Thiessen wrote:
> }
> }
> } On Sat, 23 Aug 2003, Jeremy Turner wrote:
> }
> } > On Sat, 2003-08-23 at 06:25, Justin Thiessen wrote:
> } > > You will almost certainly want to use xvidtune to tweak these, and you can
> } > > guarantee that you get the highest possible refresh rates this way.
> } >
> } > So the only way to tweak refresh rates is to use modelines?  I thought
> } > xfree86 made leaps and bounds with the modes line to specify
> } > resolutions, but being able to specify refresh rates like that would be
> } > slick.  I've never tweaked that before, only kept the default rates.
> }
> } _Specifying_ actual refresh rates for a given resolution, and asking X
> } to generate a mode, does not really seem to be the way things are set up
> } under XFree86.  As you probably know, refresh rate, along with
> } horizontal and vertical resolution, are not independent.  Your monitor has
> } a set maximum amount of bandwidth it can handle, which is manipulated
> } within the constraints of minimum and maximum horizontal and vertical
> } frequencies, minimum allowable sync pulse times, and blanking intervals to
> } produce a display.  The XFree86 Video Timing HOWTO does an ok job of
> } covering this.
>
>
> Most modern monitors are smart enough to report what scan rates then

Yeah, and even if your graphics card's module isn't DDC compliant, you
can apparently use the "read-edid" program to get this info from your monitor.

http://john.fremlin.de/programs/linux/read-edid/

> can handle.  A gui like Xconfigurator or whatever can then use this
> information to properly setup the xmodelines.  I have some very very
> picky monitors at work, and this is the only sane way to make them work.

Hm.  I've never been unable to work out a modeline by hand, if necessary.
What sort of monitors are you running?  (I'm genuinely curious.)

Justin Thiessen
thiessen at sonic.net