VMD-L Mailing List

From: Dave Schall (schalljd_at_gmail.com)
Date: Mon Aug 29 2011 - 13:53:05 CDT

Yes, stereo = 10.

What I have noticed is that when I turn "force full gpu scaling" in Nvidia
x-server settings (under gpu/dfp) off the glitch goes away and the refresh
rate goes from 99 to 120. However with scaling off, the glasses do not work
(as if they are not receiving a signal), even though the emitter is bright
green.

xrandr output is a little confusing:
schall2_at_l30897-ou:~$ xrandr
Screen 0: minimum 320 x 175, current 1920 x 1080, maximum 1920 x 1080
default connected 1920x1080+0+0 0mm x 0mm
   1920x1080 50.0* 51.0 52.0 53.0 54.0

Does that mean that it thinks it is connected at 50hz?

Looking at Xorg.0.log doesn't appear to have any warnings (WW) or notices
(!!) related to the monitor, device, or screen settings.

Not sure what else to look at. I'll take a look at overriding the EDID
settings. See if disabling them helps. Again, the images jump with or with
out the glasses. Probably not a refresh rate issue between the glasses /
screen. I think I'll try over on the nvidia forums next.

Thanks, Dave

On Mon, Aug 29, 2011 at 11:37 AM, Axel Kohlmeyer <akohlmey_at_gmail.com> wrote:

> On Mon, 2011-08-29 at 10:28 -0400, Dave Schall wrote:
>
> hi dave,
>
> > I am running ubuntu 10.04 with a quadro 4000 gpu, nvidia's 3d vision
> > glasses, and an acer GD235hz monitor. The gpu and emitter are synced
> > via the 3 pin connector as directed. Through many trials and
> > tribulations (and many edits to my xorg.conf file), I got 3d viz to
> > work, ... sort of. Approximately every 2 seconds the image jumps on
> > the screen. It is visible with and with out the glasses. It happens
> > both in VMD and when running glxgears -stereo. It must be a setting
> > somewhere but I can't find any info anywhere describing a fix for the
> > problem. Any VMD users have any tips?
>
> so i guess you have set the stereo mode in xorg.conf to 10, right?
>
> >
> > The only clue I have is that the refresh rate in the xorg.conf file is
> > set to 120 hz, while the actual refresh in the nvidia setup tool is
> > listed as 99.something. I wonder if the combination of refresh rate
> > and resolution 1920x1080 isn't allowed for some reason. It should be
> > according to the monitor specs.
>
> what does xrandr say about the refresh rate?
>
> also, have a look at the output in /var/log/Xorg.0.log
> there is usually a log entry if something that is configured
> doesn't work, or some setting skipped. in fact, most of the
> time there is too much output, so it may be hard to find the
> one setting that you need.
>
> whether the screen's spec support it or not, is usually
> not relevant, but rather whether its EDID setting allows
> this. those may be in error or set up more conservative
> than what the documentation says.
>
> there are different ways to work around "wrong" EDID settings
> (which xorg drivers will by default prefer over any user settings),
> one example is referenced here (in order to fake the presence of
> a screen entirely).
> http://sites.google.com/site/akohlmey/random-hacks/nvidia-gpu-coolness
>
> cheers,
> axel.
>
> >
> > Thanks for the help,
> >
> > Dave
> >
> > --
> > J. David Schall, Assistant Professor
> > Dept. of Mechanical Engineering, Oakland University
> > 130 DHE, Rochester, MI 48309
> > 248-370-2870
>
> --
> Dr. Axel Kohlmeyer
> akohlmey_at_gmail.com http://goo.gl/1wk0
>
> Institute for Computational Molecular Science
> Temple University, Philadelphia PA, USA.
>
> 

-- 
J. David Schall, Assistant Professor
Dept. of Mechanical Engineering, Oakland University
130 DHE, Rochester, MI 48309
248-370-2870