KVM switches and X

[Marcus Brubaker]

I had trouble with a manual switch a while back.  It turned out that the
runs of cable I had were too long and were running too close to power
cables and the like.  You're likely seeing signal loss due to the long
amount of wire between your card and the machine.  Good KVMs compensate
by boosting the signal within the box.  Bad KVMs well...don't.  So maybe
try some shorter monitor cables?  I'd be willing to bet you see the same
results if you chained two cables together directly to the video card,
skipping the KVM.

On Wed, 2004-05-12 at 12:06, Fraser Campbell wrote:
> Hi,
> 
> I recently hooked up a new KVM and I am getting horrible video when in X.  In 
> text mode things appear to be fine.  Doing a bit of research I found claims 
> that KVM switches often don't provide enough "bandwidth" for high refresh 
> rates such as those used by X.
> 
> The effect that I am seeing is a bright glow (shadow?) around all fonts, it's 
> very hard on the eyes and I start getting a headache after minutes.  Other 
> than this font problem X displays correctly.  If I plug the monitor directly 
> into my desktop then X is fine, I've tried different cables and different 
> ports in the KVM to no avail.
> 
> I tried reducing X's resolution and refresh rates to the point where I had 
> quite annoying flicker but the ghosted fonts problem remained.  Does anyone 
> have an idea if this is solveable?  The KVM is a miniview ultra (apparently 
> made by IOGear).
> 
> I'm using xfree86 4.3.0 under Debian testing.  Another guy used this switch 
> under X before I did so that's why I'm thinking there might be a solution.
> 
> Thanks
-- 
Marcus Brubaker <marcus.brubaker-H217xnMUJC0sA/PxXw9srA at public.gmane.org>

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