Originally Posted by openmedia
You need to do the following
1. Set DISPLAY to the monitor you want to make your changes
nvidia-settings -c :0.0
You should then pull up the settings for the locally attached display. This works well over X Forwarding when debugging display output with live tv.
You can do it the other way too, by setting DISPLAY=:0.0 and running nvidia-settings -c localhost:10 (or whatever your SSH forwarded display is) on your local machine. It's a little quicker because the part you're interacting with is running locally and only the NV-CONTROL queries are going over the remote connection.