Re: [Dri-users] Matrox G450 and Refresh rates

[Jeffrey W. B. <jw...@ac...>]

On Tue, 9 Jan 2001, Dave Smith wrote:

> Greetings all..
>
> I recently acquired a G450 dual-head card and have been having some
> interesting issues with getting the refresh rates setup on XF4. While
> the dual-head setup works, the refresh rates of the two monitors (which
> are both ViewSonic E771s) are always ~1Khz of on the horizontal refresh
> rate and ~2Hz off on the vertical rate. The second head always lags
> behind.
>
> It makes for a frustrating resonance between the two monitors -- is there
> anything I can do? Any driver I can recompile?
>
> I'm using XF4.02 w/ matrox's latest (1/3?) driver (mga_drv.o).
>
> Any help would be greatly appreciated.. :)

This is unlikely to have anything to do with the DRI, perhaps you would
have more luck at xp...@xf....

That said, perhaps the refresh of the first head exceeds the capabilities
of the refresh of the second head.  If the 450 is anything like the 400,
the second head's RAMDAC is very limited.  Try setting both heads to very
low pixel clocks and see what happens.

Also I am curious as to what X thinks the resolutions are.  In your log
(/var/log/XFree86.0.log), does the X server claim to be setting the scan
rates to the same or different values?

-jwb