W520 Tri-head Display Setup, Nvidia Driver Power 2 External Monitors

1. Originally want to setup a xorg.conf file using
http://zachstechnotes.blogspot.com/2012/01/tri-head-display-on-linux-thinkpad-w520.html

2. Then found this using Bumblebee etc,
http://judsonsnotes.com/notes/index.php?option=com_content&view=article&id=673:triple-head-monitors-on-thinkpad-t520&catid=37:tech-notes&Itemid=59

3. Then noticed the post with more reference.
http://zachstechnotes.blogspot.com/2012/04/post-title.html

Finally got it to work, not like 2's approach with Intel driver control 2 monitors (can not make it work), I must use Nvidia driver to control 2 external monitors.

After patched xserver-xorg-video-intel, xrandr lists LVDS1, VGA1 and VIRTUAL, but VGA1 is always disconnected no matter how I change /etc/X11/xorg.conf.

I can get 1 external monitor (which is always the one connected to VGA port) to work by as in http://sagark.org/optimal-ubuntu-graphics-setup-for-thinkpads/

Noticed BOTH external moniters wake up (indicator light from yellow to blue) to grey (black) screen, this seems they are controlled by Nvidia driver.

Reading  https://github.com/Bumblebee-Project/Bumblebee/wiki/FAQ, using

optirun nvidia-settings -c :8

indeed verify Nvidia displays 2 external monitors, and I can set twinview etc.

Why only one external monitor show stuff, and the other is grey?

Rescue comes just from xrandr, the key is to assign a larger resolution to VIRTUAL, and twinview within those 2 external monitors works:
https://wiki.ubuntu.com/X/Config/Resolution#Dynamically_setup_with_xrandr

$ cvt 3840 1080 60
# 3840x1080 59.96 Hz (CVT) hsync: 67.16 kHz; pclk: 346.00 MHz
Modeline "3840x1080_60.00"  346.00  3840 4088 4496 5152  1080 1083 1093 1120 -hsync +vsync

$ xrandr --newmode "3840x1080"  346.00  3840 4088 4496 5152  1080 1083 1093 1120 -hsync +vsync
$ xrandr --addmode VIRTUAL 3840x1080

1 comment:

Daniel S. Haischt said...

You would achieve the same if you would use thinkdisp accompanied by an /etc/thinkdisp/config.ini that contains the custom 3840x1200 resolution.