[ltp] external monitor is blurred!

[Alex Deucher]

On Wed, 22 Dec 2004 14:26:54 -0700, Ben Pearre
<bwpearre@alumni.princeton.edu> wrote:
> I finally searched the archives and set up my R40 to talk to an
> external monitor (Dell 2000FP flat panel).  The monitor takes digital
> input, so I'm very sad that the Thinkpad doesn't have a DVI out, and
> this is indeed a problem.
> 
> I've set the monitor to not scale incoming images when they are less
> than the monitor's native 1600x1200, so there are no antialiasing
> problems.  I guess I could scale 800x600...
> 
> In anything over 1024x768 the monitor only gets a fuzzy, shimmering
> image.  Not unusable, but very far from crisp: looks like a really
> cheap analog monitor.  And the default X background ("stipple")
> shimmers unbearably in horrible vertical stripes.
> 
> I don't have much spare computer equipment here, so I can't isolate
> the component that's causing the problem.  But I assume it's at least
> one of:
> 
> * Dell uses cheap a crappy ADC in the monitor
> 
> * The analog monitor cable is poor (it's thinner than many I've seen
>   and may be unshielded or poorly shielded but it does have the
>   ferrous lumps at both ends).
> 
> * The Thinkpad has a crappy DAC that doesn't like high resolutions
>   (how do I find out what the refresh rate is?  Does anyone have a
>   ModeLine that lowers it?)  /var/log/XFree86.x.log suggests that I'm
>   running at 60 Hz, but I do get "(WW) (1600x1200,Dell) mode clock
>   162MHz exceeds DDC maximum 160MHz" --- is this bad?
> 
> * The X software is doing something funny
> 

you might try the DisplayPriority option, see the radeon man page for
more on that.  You also might want to try running the monitor at 50 or
55 Hz.

Alex

> The problem persists when I unload the Atheros drivers, so at least
> it's probably not interference from those...
> 
> Can anyone here answer at least for the third and fourth bullets?  Is
> there a non-DDC modeline that works better?
> 
> Thanks much!  And happy solstice :)
> 
> --
> Ben Pearre          http://hebb.mit.edu/~ben       PGP: CFDA6CDA
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