Questions about duplicate monitors

[SteveSmith1980]

So I just connected my PC to my TV for the first time. I have two questions right now.

If both monitors are working at the same time (duplicate monitors), does the PC work harder? Is it more taxing for the system? Is it more taxing for things like the CPU, graphic card, etc...?

My other question is about the sound. I have to go into Windows 7 options to change the "default" playback device between my PC speakers and HDTV. I am not able to get sound on both devices at the same time. Is this possible? It would save me time, as I would not have to go into Windows options each time I switch between the two screens.

 

[americanaudiophile]

I would guess that running two separate displays is a bit for work but I have a modest Toshiba laptop with mobo video running its display and a projector at the same time with no issues.
On that same laptop (Win7 home) which is connected via HDMI to the system if I have it set to output audio via HDMI and that HDMI is not selected for viewing the audio comes from the laptop speakers and reverts to the HDMI when it is connected. Try that. Otherwise you will have to select it manually. Microsoft has never allowed for more than one simultaneous audio output. Don't know why since it would be useful.