Dualscreen on Gentoo for Dell optiplex 3020

dualscreen.sh

#!/bin/sh
# Add mode 1080p on Gentoo for Dell optiplex 3020
# to get the values use: gtf 1920 1080 60
# 1920x1080 @ 60hz
xrandr --newmode "1920" 172.80  1920 2040 2248 2576  1080 1081 1084 1118 -hsync +vsync
xrandr --addmode VGA1 1920
xrandr --output HDMI1 --off --output VIRTUAL1 --off --output DP1 --mode 1920x1080 --pos 0x0 --rotate normal --output VGA1 --mode 1920 --pos 1920x0 --rotate normal

# on "xrandr: Configure crtc 0 failed" change to 50hz
# gtf 1920 1080 50