Are you doing this just to "save" power? What's the end-goal?
Even if you have the display off, the card will be idle. It's not going to be like the card isn't installed at all (GCN AMD graphics cards with ZeroCore get very close in "display off" conditions, but you're only talking about 15W "idle" power draw from the 560Ti). See here for some power consumption comparisons.
Most 2D desktop uses can be considered "idle" work, while gaming would be the "full load" category. As you can see, the difference between "idle" and "display off" (monitor input switched to the IGP here) are minimal/negligible for your card. You also have to consider that the IGP will now be running. (I would imagine Intel CPUs can completely gate off the IGP if it's not being used)
TLDR; If saving power is your motivation for this thread, even though switching the input on your monitor is easy, it probably won't save much power over just leaving the dGPU plugged in. If you have a Power Meter I'd be interested to know how much it actually saves though.
Look to turn off a 60W light bulb somewhere in the house/apartment that doesn't need to be on while you're using your computer instead.
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