[ubuntu] 14.04 - Resolution change

Hello!

I have installed ubuntu 14.04 on a chromebox, and I had noticed that the machine is not powerful enough for the resolution of the 4k T.V I hooked it up to (3840 x 2160) . The mouse & keyboard become quite laggy at this resolution, so I have lowered it to 1080p through the display manager and this seems to help a lot.

However, I get error messages on startup and stays at 3840x2160. (could not apply the stored configuration for monitors).

To bypass problem I have tried to execute this script at startup:

cvt 1920 1080 60

xrandr --newmode "1920_1080_60.00" 173.00 1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync

xrandr --addmode HDMI1 1920_1080_60.00

 xrandr --output HDMI1 --mode 1920_1080_60.00

Is there anything I can do to force this resolution change?

Thank you

Cat