Usually, a home PC capable of gaming would be quite power hungry when turned on, such that you wouldn't also want to leave it on when you were not around.
And that graphics card would also be wasting power (and making fan noise) when using the PC for web browsing / video streaming etc. Such activities are better handled by the integrated graphics.
So my question is, is it possible to set up a home PC, single monitor, such that the graphics card is normally powered off (integrated graphics in use normally), until you launch the game? (No rebooting, no fiddling with monitor source)
BTW, are some laptops capable of this?