A green mode

I have noticed that my four processors are always working after loading a project including virtual synths and/or effects. I mean, even if I'm doing nothing, watching TV, drinking coffee or reading my e-mail on my smartphone without playing the project, my PC is working hard... It's not the case if I load a MIDI-only sequence, which is supposed to be played by my hardware synth : only one processor is working a little bit.
 
Sometimes you even get a noise created by some plugins, while the song is not playing.
 
I think that this behaviour should be an option. If I want my DAW to be immediately ready to work, it is interesting, but if not, why does it happen? I think it's a waste of energy and money, it makes my PC works a lot without any reason, and its fans too...
 
I think that there should be a green button to say "if I don't hit play for x minutes the processors can relax a little bit"... Obviously in a live or hard working environment I would disable this option.

Sonar is rather smart is decision either call some plug-in or not. But,
a) if there is a route from echo enabled audio input or there is a possibility some plug-in is a "generator", the whole chain should continue to work
b) you jamming/recording for a while and.... BUM, your computer went to sleep. Yes, you can unset that in Windows. But you forgot. You want yet another such option to be forgotten build into Sonar? Sonar tries to avoid that on purpose, see "Quick Edit" in the previous post