Help with resolution settings

[sktsee]

On Wed, 08 Sep 2010 09:11:41 -0700, NoOp wrote:

[snip]

> Low resolution settings typically correspond to incorrect refresh rates,
> make sure that yours are correct. On some systems I've found using the
> default 'System|Preferences|Monitor/Display' rather than the nVidia
> manager works - don't know why, but seems to do the trick on occasion.

Use of xrandr and a gui front-end which uses it like gnome-display-
properties, with Nvidia's 3D binary driver (whether installed using 
Nvidia's native installer or Ubuntu's package) is not recommended by 
Nvidia because the driver lies about the refresh rate in order to support 
its Dynamic TwinView feature. This causes xrandr to report erroneous 
refresh rates. 
Source: /usr/share/doc/NVIDIA_GLX-1.0/README.txt

Example on my system:

With default enabled Dynamic TwinView setting

$ xrandr -q
Screen 0: minimum 320 x 240, current 1680 x 1050, maximum 1680 x 1050
default connected 1680x1050+0+0 0mm x 0mm
   1680x1050      50.0*    56.0  
   1440x900       51.0     58.0  
   1280x1024      52.0     63.0  
...

All above are incorrect and notice that each mode has a unique refresh 
rate.

With Dynamic TwinView disabled

$ xrandr -q
Screen 0: minimum 320 x 240, current 1680 x 1050, maximum 1680 x 1050
default connected 1680x1050+0+0 0mm x 0mm
   1680x1050      60.0* 
   1440x900       75.0     60.0  
   1280x1024      75.0     60.0  
...

All correct with multiple modes having the same refresh rate, which is 
what the monitor actually supports.

IIRC, gnome-display-properties stores the (virtual)screen resolution and 
refresh rate in the gconf database. Gnome-settings-daemon reads the gconf 
values upon user login and sets the display accordingly with xrandr, 
though it's using an incorrect refresh rate. I can't remember if this can 
lead to Michael's situation with what sounds like a mis-matched virtual 
screensize/display resolution problem, or something like an off-center 
screen placement. I don't really feel like dinking around with my setup 
to find out, though. Anyway, when using the Nvidia 3D driver, I find it's 
best to just use nvidia-settings to make any xserver adjustments so to 
avoid any pitfalls when using an app that only recognizes a small subset 
of the driver's features.

-- 
sktee