How much power does LucidLogix Virtu MVP i-mode save over discrete GPU

I just ordered a 3770k and P8Z77-M PRO while i waited for the Trinity which now the local retailer says is far from launch :( AMD you suck i waited for you trinity... Now to the point the P8Z77-M PRO has LucidLogix Virtu MVP which is interesting and since most of my setup's have a discrete GPU i want to save as much electricity as possible.

While reading on LucidLogix Virtu MVP i found out about the i mode which will force the system use the HD4000 instead of the GTX 570, now how much of a Watt difference are we talking about anyone took a digital measure on how much Watt difference the LucidLogix Virtu MVP i-mode can give over the simple GTX 570 route.