AMD 290 15.5 unable to use switchable graphics with HD 4600

Hello, the title pretty much sums it up, I'm trying to reduce the power footprint of my computer and obviously I don't need my 290 stepping up to play games like Hearthstone. Although I can't find the switchable graphics option anywhere.

The only other option I can think of without this setting is to run a monitor in the IGP output and drag hearthstone onto that monitor (The usage bumps up to 16% so my assumption is that it's been rendered with the IGP)

Does anyone know how to enable the switchable graphics on a desktop?

I think that option's for laptops only, but according to Anandtech the idle system power usage for a 290 on their test PC is 87 watts, so assuming you can keep it at 2D clocks it shouldn't really use much power compared to the CPU. You could probably just set a manual Afterburner profile with low clocks, although I think if the monitor the game's running in is on the IGP it should be using that instead. What are you using to measure the GPU usage? I think HWINFO64 should be able to show you a breakdown of which chip is active in sensors-only mode. At any rate if it's running on the IGP monitor and the IA/GT Intel cores bump in power usage but the 290 stays low that should indicate that it's using the IGP.

I was using GPU-Z's usage which would spike when I dragged it across.
GPU-Z also shows power usage (V and A into the card) 10W idle and 25W with hearthstone.