I am writing this for everyone that may have the same problems that I had (I hope it is not duplicating other efforts, but maybe redundant documentation isn't all bad?).
My Problem:
1.) The GDM login screen was not centered after reboots (I had to press the "AUTO" button on my 19" widescreen LCD monitor).
2.) The GDM screen always "flickered" as if it was out of "vsync".
3.) The screen resolution refused to change from 640x480 when I started KDE (but if I used xrandr or grandr to change it, I could get 1440x900 without any problems). This part of the problems only happened with KDE (not Gnome). This only happened with one user account.
My Hardware:
19" Widescreen LCD Monitor Q19wb
Dual Nvidia GeForce 8500GTs (256 MB) in SLI
AMD 64 X2 5400+
GIGABYTE GA-M57SLI-S4 Motherboard
Other Notes:
Part of the problem (640x480) was probably caused by my mistake: I installed the real time kernel without the appropriate modules and started the computer. It gave me a message about being in "low resolution" mode (or something similar) and I pressed continue. The other problems with the flicker were there from a fresh install (before the new kernel). I am using the latest "nvidia-glx-new" package from synaptic (with universe, multiverse, & medibuntu in my repositories). The restricted driver is turned on in the "Hardware Drivers Manager". I am running 8.04. After resizing with xrandr, hardware acceleration works well and I didn't see any flicker in KDE with Compiz-Fusion or UrbanTerror or other 3D games/applications.
Things that didn't work:
I tried many different changes to the /etc/X11/xorg.conf file like adding these to the "Device" section:
#Option "NvAGP" "0"
#Option "SLI" "AFR"
#Option "Coolbits" "1"
#Option "NoLogo" "false"
#Option "RenderAccel" "1"
#Option "BackingStore" "true"
#Option "UseCompositeWrapper" "true"
#Option "DamageEvents" "false"
#Option "NoFlip" "1"
#Option "AllowGLXWithComposite" "1"
I also made a lot of changes to the modelines to the "monitor" section like this:
modeline "1440x900_50.00" 87.41 1440 1512 1664 1888 900 901 904 926 -HSync +Vsync
modeline "1440x900_51.00" 89.26 1440 1512 1664 1888 900 901 904 927 -HSync +Vsync
modeline "1440x900_52.00" 91.11 1440 1512 1664 1888 900 901 904 928 -HSync +Vsync
modeline "1440x900_53.00" 92.86 1440 1512 1664 1888 900 901 904 928 -HSync +Vsync
modeline "1440x900_54.00" 94.71 1440 1512 1664 1888 900 901 904 929 -HSync +Vsync
modeline "1440x900_55.00" 97.28 1440 1520 1672 1904 900 901 904 929 -HSync +Vsync
modeline "1440x900_60.00" 106.47 1440 1520 1672 1904 900 901 904 932 -HSync +Vsync
but none of these things fixed the issue. I also tried changing the settings in "System Settings" -> "Monitor & Display".
(when I noticed that it was only one user I knew that there must be something in that user configuration).
*****************************************
Solution:
*****************************************
See the xorg.conf file below for the flicker. What I found was the settings were incorrect in kcontrol (type in terminal or ALT+F2) under "Peripherals" -> "Monitor & Display". When I had the modelines in the xorg.conf file and then set the correct mode in kcontrol it was all fixed!
My current /etc/X11/xorg.conf
My Problem:
1.) The GDM login screen was not centered after reboots (I had to press the "AUTO" button on my 19" widescreen LCD monitor).
2.) The GDM screen always "flickered" as if it was out of "vsync".
3.) The screen resolution refused to change from 640x480 when I started KDE (but if I used xrandr or grandr to change it, I could get 1440x900 without any problems). This part of the problems only happened with KDE (not Gnome). This only happened with one user account.
My Hardware:
19" Widescreen LCD Monitor Q19wb
Dual Nvidia GeForce 8500GTs (256 MB) in SLI
AMD 64 X2 5400+
GIGABYTE GA-M57SLI-S4 Motherboard
Other Notes:
Part of the problem (640x480) was probably caused by my mistake: I installed the real time kernel without the appropriate modules and started the computer. It gave me a message about being in "low resolution" mode (or something similar) and I pressed continue. The other problems with the flicker were there from a fresh install (before the new kernel). I am using the latest "nvidia-glx-new" package from synaptic (with universe, multiverse, & medibuntu in my repositories). The restricted driver is turned on in the "Hardware Drivers Manager". I am running 8.04. After resizing with xrandr, hardware acceleration works well and I didn't see any flicker in KDE with Compiz-Fusion or UrbanTerror or other 3D games/applications.
Things that didn't work:
I tried many different changes to the /etc/X11/xorg.conf file like adding these to the "Device" section:
#Option "NvAGP" "0"
#Option "SLI" "AFR"
#Option "Coolbits" "1"
#Option "NoLogo" "false"
#Option "RenderAccel" "1"
#Option "BackingStore" "true"
#Option "UseCompositeWrapper" "true"
#Option "DamageEvents" "false"
#Option "NoFlip" "1"
#Option "AllowGLXWithComposite" "1"
I also made a lot of changes to the modelines to the "monitor" section like this:
modeline "1440x900_50.00" 87.41 1440 1512 1664 1888 900 901 904 926 -HSync +Vsync
modeline "1440x900_51.00" 89.26 1440 1512 1664 1888 900 901 904 927 -HSync +Vsync
modeline "1440x900_52.00" 91.11 1440 1512 1664 1888 900 901 904 928 -HSync +Vsync
modeline "1440x900_53.00" 92.86 1440 1512 1664 1888 900 901 904 928 -HSync +Vsync
modeline "1440x900_54.00" 94.71 1440 1512 1664 1888 900 901 904 929 -HSync +Vsync
modeline "1440x900_55.00" 97.28 1440 1520 1672 1904 900 901 904 929 -HSync +Vsync
modeline "1440x900_60.00" 106.47 1440 1520 1672 1904 900 901 904 932 -HSync +Vsync
but none of these things fixed the issue. I also tried changing the settings in "System Settings" -> "Monitor & Display".
(when I noticed that it was only one user I knew that there must be something in that user configuration).
*****************************************
Solution:
*****************************************
See the xorg.conf file below for the flicker. What I found was the settings were incorrect in kcontrol (type in terminal or ALT+F2) under "Peripherals" -> "Monitor & Display". When I had the modelines in the xorg.conf file and then set the correct mode in kcontrol it was all fixed!
My current /etc/X11/xorg.conf
Code:
Section "ServerLayout" Identifier "Default Layout" screen 0 "screen1" 0 0 Inputdevice "Generic Keyboard" Inputdevice "Configured Mouse" EndSection Section "Files" EndSection Section "Module" Load "extmod" Load "vbe" Load "glx" Load "v4l" EndSection Section "InputDevice" Identifier "Generic Keyboard" Driver "kbd" Option "CoreKeyboard" Option "XkbRules" "xorg" Option "XkbModel" "pc105" Option "XkbLayout" "us" EndSection Section "InputDevice" Identifier "Configured Mouse" Driver "mouse" Option "CorePointer" Option "Device" "/dev/input/mice" Option "Protocol" "ImPS/2" Option "ZAxisMapping" "4 5" #Option "Emulate3Buttons" "true" EndSection Section "Device" Identifier "nVidia0" Driver "nvidia" Vendorname "nVidia Corporation" Boardname "nVidia Corporation G80 [GeForce 8500 GT]" BusID "PCI:3:0:0" EndSection Section "Device" Identifier "nVidia1" Driver "nvidia" Vendorname "nVidia Corporation" Boardname "nVidia Corporation G80 [GeForce 8500 GT]" BusID "PCI:2:0:0" EndSection Section "monitor" # Identifier "monitor1" Vendorname "Plug 'n' Play" Modelname "Plug 'n' Play" modeline "640x480_52.00" 20.18 640 648 712 784 480 481 484 495 -HSync +Vsync modeline "800x600_52.00" 32.45 800 824 904 1008 600 601 604 619 -HSync +Vsync modeline "1024x768_52.00" 54.69 1024 1072 1176 1328 768 769 772 792 -HSync +Vsync modeline "1440x900_50.00" 87.41 1440 1512 1664 1888 900 901 904 926 -HSync +Vsync modeline "1440x900_51.00" 89.26 1440 1512 1664 1888 900 901 904 927 -HSync +Vsync modeline "1440x900_52.00" 91.11 1440 1512 1664 1888 900 901 904 928 -HSync +Vsync modeline "1440x900_53.00" 92.86 1440 1512 1664 1888 900 901 904 928 -HSync +Vsync modeline "1440x900_54.00" 94.71 1440 1512 1664 1888 900 901 904 929 -HSync +Vsync modeline "1440x900_55.00" 97.28 1440 1520 1672 1904 900 901 904 929 -HSync +Vsync modeline "1440x900_60.00" 106.47 1440 1520 1672 1904 900 901 904 932 -HSync +Vsync modeline "1280x768_52.00" 68.53 1280 1336 1472 1664 768 769 772 792 -HSync +Vsync modeline "1280x768_53.00" 69.85 1280 1336 1472 1664 768 769 772 792 -HSync +Vsync modeline "1280x768_54.00" 71.26 1280 1336 1472 1664 768 769 772 793 -HSync +Vsync modeline "1280x768_55.00" 72.58 1280 1336 1472 1664 768 769 772 793 -HSync +Vsync modeline "1280x768_60.00" 80.14 1280 1344 1480 1680 768 769 772 795 -HSync +Vsync Gamma 1.0 EndSection Section "screen" # Identifier "screen1" Device "nVidia0" Defaultdepth 24 Monitor "monitor1" SubSection "Display" Depth 24 #Virtual 1920 1200 Modes "1440x900_60.00" EndSubSection EndSection Section "ServerFlags" EndSection