Is there a way to turn one monitor off in a dual-head setup?

Question

Is there a DPMS option to turn one monitor off in a dual-head setup? I know the following can turn both off:

xset dpms force off

Answer 1

xrandr --output $NAMEOFDISPLAY --off

Answer 2

If you are using the nvidia driver, you can use twinview metamodes. You can find everything in the driver manual. After configuring, you can switch by using

xrandr -s 1

or use a 0 if you want to switch back.

Answer 3

You can use ddccontrol to control dpms on individual monitors – without modifying the virtual desktop (→ moving windows etc.).

See my answer on a question that explicitly asked for this behaviour.