Control Panel → Display can be used to configure the system to run the display wizard the next time the system boots. This allows you to reconfigure your video driver and display settings.
If you click this icon in Control Panel, you will receive the message shown in Figure 8.14a.
Select “Yes” which will prompt for your password. You should then save your work and reboot the system.
Alternately, you can use the boot menu to start the display wizard. As soon as the system starts to boot, press ESC to access the GRUB boot menu. Unless you are dual booting or have configured boot environments, there will be one entry named "PC-BSD (default) in the boot menu. Press enter and select "Run the Display Wizard" from the menu.Regardless of whether you started the Display Wizard from Control Panel or from the boot menu, it will finish booting the system and then prompt you to confirm the resolution if it finds an optimal one. To configure a different resolution, click “No” to access the display wizard, shown in Figure 8.14b.
This screen can be used to select the desired screen resolution, color depth, and video driver. If you select the "vesa" driver, it will always work but will provide sub-optimal performance. Click on the drop-down menu to select the driver that most closely matches your video card name.
You can also use the drop-down menus to change the screen resolution and color depth values. If the value you desire is not listed, it may be that the selected driver does not support that resolution or depth.
Advanced users can select their monitor's horizontal sync and vertical refresh rate in the "Advanced" tab, seen in Figure 8.14c:
Use caution and refer to your monitor's documentation if you make any changes here. If you are not sure what you are doing, leave the default values as-is.
If your computer is connected to two monitors, check the box "Enable Dual-Head support".
When you are finished, click the "Apply" button for your settings to be tested. If anything goes wrong during testing, you should be taken back to the "Display Settings" screen so that you can try another setting. Once you are satisfied with the settings, click "Yes" when prompted to accept them.
Desktop Effects and Compositing
To prevent problems with video cards that do not support them, desktop effects (used by KDE) and compositing (used by other window managers) are disabled by default. You can change this default if your video card supports desktop effects.
Check the box "Enable desktop effects at startup". You can use the "All Effects" tab to get more information about each possible effect and to enable the effects that interest you.
If XFCE is installed, you can enable compositing from any logged in desktop. Go to Control Panel
➜ Window Manager Tweaks ➜ Compositor. If Window Manager Tweaks does not appear in the Control Panel menu, use the desktop selector drop-down menu to select "All" or "XFCE".
In the screen shown in Figure 8.14e, check the "Enable display compositing" box to enable the compositing options.
If you are having problems with your display settings and would like to manually edit /etc/X11/xorg.conf or run Xorg --config, first tell the PC-BSD® system to not automatically start X. You can temporarily stop your current X session and prevent additional sessions from starting by typing this command as the superuser:
This will drop you down to a console where you can try the instructions in theto manually configure and test Xorg. Once you have a configuration that works for you, save it to /etc/X11/xorg.conf, and restart gdm to test the configuration:
If your graphics white-out after a suspend or resume, try running this command as the superuser:
If that fixes the problem, carefully add this line to /etc/sysctl.conf:
If the monitor goes blank and does not come back, try running this command as your regular user account:
If that fixes the problem, add that line to the .xprofile file in your home directory.