login screen stuck at 60Hz with CRT monitor

[klerfayt]

60Hz on CRT is extremely unpleasant, adding modelines with higher refresh rate to xorg.conf file won't help

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: lightdm 1.2.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu2
Architecture: amd64
Date: Fri Apr 13 13:27:40 2012
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: lightdm
UpgradeStatus: Upgraded to precise on 2012-04-12 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Christian Kroll (tunix79)]

The X server starts with the correct vertical refresh rate (according to the log) and then it gets changed to 60 Hz as soon as the Unity greeter shows up. It stays that way in the desktop session (which is XFCE4 in my case) and I have to correct the refresh rate manually with Nvidia's configuration tool. While this is a non-issue for TFT owners, it is really painful for CRT users like me.

[klerfayt (klerfayt-deactivatedaccount)]

For desktop session try to change resolution in display settings from higher to lower resolution and back to higher again. This should get you higher refresh rate permanently.

[Eimann (eimann)]

klerfayt, your explanation doesn't make sense to me. Nevertheless I tried to verify your advise but failed. It is still forced to 60Hz by unity-greeter.

[klerfayt (klerfayt-deactivatedaccount)]

@Eimann, the explanation is strictly for desktop settings, not login screen

[Coolebrax (coolebrax)]

It happens the same, although I set the screen at 85 Hz with nvidia-settings after reboot always comes back to 60 hz.
In the xorg.conf file is correctly set to 85 hz. Please help, it is important for those who have CRT monitors.

[Coolebrax (coolebrax)]

I now installed and configured GDM as default DM and problem solved.
The problem is caused only LightDM.
Now do not come back at 60 Hz, runs at 85 hz. perfectly.

[Nelux (manolollr)]

It works if you disable the "DynamicTwinView" option. You must edit the file /etc/X11/xorg.con and add the following line in Section "Screen":

Option "DynamicTwinView" "False"

Here is an emxample of my xorg.con:

Section "Screen"
    Identifier "Screen0"
    Device "Device0"
    Monitor "Monitor0"
    DefaultDepth 24
    Option "TwinView" "0"
    Option "TwinViewXineramaInfoOrder" "CRT-1"
    Option "metamodes" "1440x900_75 +0+0"
    Option "DynamicTwinView" "False"
    SubSection "Display"
        Depth 24
    EndSubSection
EndSection

[Christian Kroll (tunix79)]

I can confirm Nelux' observation. After turning this option off the refresh rate stays the same when the unity greeter is launched. Maybe a bug in Nvidia's driver?