Does this explain TV-Out configuration?

Does this explain TV-Out configuration?

Does the TV Out display the same thing as the monitor? If so, then there's probably only one display generation pipeline that feeds to multiple physical outputs. My interpretation of the CRTC abstraction is that it also allows a single display controller to control multiple heads, each potentially displaying something different.

Even then it seems like you might get into restrictions on refresh rates or pixel clocks between the two outputs if there is only one pixel clock source, or if there are synchronization requirements between the two pipelines during refresh. I haven't looked closely at modern display hardware, though, so I really couldn't say.