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The initial Gigabyte Z68 MOBO's lacked ALL iGPU features e.g. GA-Z68X-UD7, so Quick Sync would never work on those MOBOs, byt all Z68's have SSD Caching regardless of iGPU. The ones you linked above all have various iGPU connectivity e.g. 1 x HDMI or 1 x HDMI/D-Sub + DVI/1 x DisplayPort. My recommendation is to read VERY carefully
The 'P' only have 1 x HDMI iGPU connections.
Here's an easy to read side-by-side comparisons -> http://www.newegg.com/Product/Productcompare.aspx?Submit=ENE&N=100007627%2050001314%20600093976%20600158412&IsNodeId=1&bop=And&CompareItemList=280|13-128-499