following this article on pi you make edits to
$sudo nano /boot/config.txt
Which values are valid for my monitor?
Your HDMI monitor may only support a limited set of formats. To find out which formats are supported, use the following method:
Set the output format to VGA 60Hz (hdmi_group=1 and hdmi_mode=1) and boot up your Raspberry Pi
Enter the following command to give a list of CEA-supported modes: /opt/vc/bin/tvservice -m CEA
Enter the following command to give a list of DMT-supported modes: /opt/vc/bin/tvservice -m DMT
Enter the following command to show your current state: /opt/vc/bin/tvservice -s
Enter the following commands to dump more detailed information from your monitor: /opt/vc/bin/tvservice -d edid.dat; /opt/vc/bin/edidparser edid.dat
The edid.dat should also be provided when troubleshooting problems with the default HDMI mode.
the right settings in combination with the rigth videoformat should lower ‚calulation cost‘ of pi
eg. screen res = 1920 x 1080p –> hdmi_group=2, hdmi_mode=82 + videofile in 1080p should run smoothly (also when looping with eg. omxplayer –loop)
sideinfo:
to check cputemperature etc do
vcgencmd measure_temp
vcgencmd measure_volts
vcgencmd measure_clock arm
available commands with: vcgencmd commands