because QuickSync boosts the CPU compute performance to no end
Only for gpu accelerated applications that can use it like HD video decoding/transcoding, like quicksync was designed to do. It doesn't help with any cpu related computations. Right now, most sandy bridge versions (mobo's depended) will disable the gpu core of the Intel HD's when you use a discrete card automatically and have your monitor plugged into the discrete card.
Though I wonder why you couldn't just use the discrete GPU (maybe the CPU knows how to schedule instructions properly for the integrated GPU?)
You can, but I believe it maybe limited to what chipset you have to be able to do this.
Lucid Virtu allows you do sync your monitor to the HD 2000+ and a discrete card (Lucid Virtu software overview
), just like nvidia mobile optimus for laptops; in theory to save power when the discrete gpu goes idle, it would literally shut it off, transfer gpu to Intel's gpu seamlessly. Also, you can still have discrete card gpu acceleration for gaming when you have the monitor plugged into the HD 2000+ gpu.
There's also limitations to the software as it may not work with all games and it has trouble with some DX11 features like tessellation. But the thing is that most modern gpu cards already have sophisticated power management and power savings mode that it really nullifies the tricky software/hardware handling for such a setup, specially when you are talking about big expensive cards only taking what 15w at idle? Plus the software can't completely shut down the entire pcie gpu lanes yet to save power like nvidia optimus can, so its hard to justify taking the small performance hit just to save a few watts at idle.