displayconfig-gtk and gnome-display-properties show incorrect refresh rate options

Bug #157623 reported by Gaspard Leon on 2007-10-27
Affects Status Importance Assigned to Milestone
displayconfig-gtk (Ubuntu)

Bug Description

Binary package hint: displayconfig-gtk

Both displayconfig-gtk and gnome-display-properties show incorrect refresh rate options.

They show 50 and 51 instead of sane options such as 60 and 75... my LCD panel says it's using 75 but displayconfig-gtk and gnome-display-properties show it as 50 (i don't think there is a 50 for this monitor)

I have tried many xorg.conf changes, but it appears displayconfig-gtk and gnome-display-properties do not use xorg.conf to lookup the refresh rate options...

Basically I would like to know where displayconfig-gtk and gnome-display-properties store their settings so I can manually define the correct options.

Anyway, the refresh rate is correct, but it would be nice if the UI displayed the correct options.

OS: Ubuntu 7.10 release
My monitor: AOC LM720 17inch LCD panel using Analog (VGA D-SUB connector) (does not support DVI)
My Video card: NVidia GeforceFX 5900XT with VGA and DVI outputs, using the VGA one.

Anything I should attach? commands to run?

Gaspard Leon (gaspard.leon) wrote :

Oh yeah, and there are extra useless resolution options like 832x624 and 896x672

For example one of the options is 1280x960, if i select it, my video card sets it ok, but the monitor goes blank and the OSD displays: "INPUT NOT SUPPORTED"... then wait for it to reset.

I think monitors are supposed to report their supported modes, so these kind of things don't happen.

Also, using nvidia-settings, when you drop-down a resolution, sane options are displayed for refresh rate, e.g. 1280x1024 @ 60 or 75...

Sebastian Heinlein (glatzor) wrote :

Please attach the output of the following commands: "xrandr -q", "sudo get-edid|parse-edit" and "sudo ddcprobe". most likeyl the commands will not run at the first time, since you perhaps have to install some additional packages.

it seems like your monitor reports the wrong infromation to the operating system.



Changed in displayconfig-gtk:
status: New → Incomplete
Gaspard Leon (gaspard.leon) wrote :

already got the packages when i was hunting for an answer...

anyway here you go

Gaspard Leon (gaspard.leon) wrote :

sudo get-edid|parse-edit results

Gaspard Leon (gaspard.leon) wrote :

sudo ddcprobe results

Gaspard Leon (gaspard.leon) wrote :

it appears the only one that is incorrect is xrandr... unless those are horizontal freq?

Gaspard Leon (gaspard.leon) wrote :

should I change this to new again now that it's "Complete"

Gaspard Leon (gaspard.leon) wrote :

Hello anyone watching this bug, should I move it back to "New" or change it to "Complete" or wait for someone to come and have a look at it..


Sebastian Heinlein (glatzor) wrote :

are you using the open source or the proprietary nvidia driver?

Gaspard Leon (gaspard.leon) wrote :

The restricted one: nvidia-glx-new

Gaspard Leon (gaspard.leon) wrote :

Does the open-source one support compiz?

Sebastian Heinlein (glatzor) wrote :

You could retry with the open source one. Perhaps this is a bug in the driver.

Gaspard Leon (gaspard.leon) wrote :

Hmm behaviour is mostly as expected with the "nv" open source driver.

the list shows 60 and 75 as refresh rate options... and 3d effects don't work anymore.

Also in 75 hz mode, the monitor's picture is displayed off-center to the right, (using auto-align), it can be manually centered, but the proprietary driver is centered correctly at this same refresh rate.. so the timings are different perhaps...
At 60 hz, the auto-center function works ok.

So... I assume the nvidia-glx-new driver reports incorrect values to displayconfig-gtk??

I have included the outputs from the 3 commands you suggested before (run after switching to open-source.)

Is this it? do I report this to another bug tracker?

Sebastian Heinlein (glatzor) wrote :

YOu should report it at NVidia's bug tracker.

Gaspard Leon (gaspard.leon) wrote :

hmm looks like it was already reported:

solution in:

Posting from work: When I get home tonight I'll try it out.

Gaspard Leon (gaspard.leon) wrote :

ok well:

Option "DynamicTwinView" "False"
(in the device section of xorg.conf)

works well... this should be the default for single monitor nvidia setups.
Thanks for your time!

Sebastian Heinlein (glatzor) wrote :

Do have got any information to back up your suggestion? How wide spread is your problem?

Gaspard Leon (gaspard.leon) wrote :

Following the information posted in the 2 forum links I posted above:

The DynmaicTwinView option defaults to ON as of nvidia driver 96xx and newer.

The effect of DynamicTwinView is (detailed in the driver README) such that the refresh rates are reported incorrectly as id numbers instead of hz values.

This works ok if you use the nvidia-settings application which is designed to get the actual hz values from the driver.

If DynamicTwinView is enabled, other then ids as hz values, the driver can support connecting say a TV dynamically and setup it's refresh rate separate from the other screen, through what it calls "metamodes", for details, the README of the driver is freely available.

In the first forum link I specified, Nvidia technicians have posted saying that this is the default behaviour and will not be changed.

So either Ubuntu's display settings pop-up continues to display incorrect hz values, which is fine, since these are closed source drivers (which I know are unsupported.)

On the other hand, if you want to enable desktop effects, you have to use the drivers.
If you then go to Screen Resolution or Screens and Graphics, your refresh rates are incorrect.

Perhaps if the user is already using the restricted drivers, we could also have a link to the nvidia-settings on the menu?

I don't know what is the best solution to this? perhaps doing nothing?

As far as how wide spread the issue is...
1. Only effects nvidia graphics card users
2. Only effects a subset of those users that want desktop-effects, or 3d support.
3. Only effects a subset of those users that don't edit their xorg.conf and use the default of DynamicTwinView ON
4. Only effects a subset of those users that use displayconfig-gtk or gnome-display-properties to change their refresh rate.

So, it will effect anyone that uses the restricted drivers manager to install nvidia, does not edit their xorg.conf, and goes to change their refresh rate using displayconfig-gtk or gnome-display-properties.

So using ballpark figures... (probably wildly incorrect)
if 30% of users use Nvidia chipsets
and 50% of those use restricted drivers to install nvidia for effects, or 3d
and 25% of those want to change their refresh rate
and 50% of those notice that 51hz does not look right
then about 2% of users will be effected.

Sorry for the long winded answer, but it's a complex issue...

Stefan Bethge (kjyv) wrote :

I think it makes sense to just add that option to xorg.conf when the nvidia module is activated in restricted driver manger.
After I activated the module under hardy, it asked me to reboot and after restarting it changed my resolution and refresh rate to really unusable values.

Gaspard Leon (gaspard.leon) wrote :

It's only a minor annoyance, just use nvidia-settings to change your resolution and refresh rate. or know that 50 and 51 hz are really just ID numbers not hertz values.

Thank you for reporting this bug and for your efforts to make
Ubuntu better. As Xorg has improved this past year, an unfortunate side
effect of these improvements is that it has rendered several design
assumptions in displayconfig-gtk obsolete. So, starting with Hardy we
are no longer putting displayconfig-gtk forth as a primary configuration
tool, and are putting our development focus into the Screen Resolution
applet. As a result, we do not plan to fix this bug and thus are closing

For more background on this change, please see this page:

Changed in displayconfig-gtk:
status: Incomplete → Won't Fix
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