Thanks, ex58, i tried the f8 bios on the z77x up4 th, it has more thunderbolt options but needs a tiny bit more juice to reach stable 4.8GHz on the cpu.
I had the f8 bios running all day yesterday and overall the f7 seems better for me, even in gaming, i guess the extra heat produced from the upped voltage was causing issues, or perhaps it was due to thunderbolt having some dedicated ram? - an option not present in f7.
All the same i'm very happy with f7, i get my gen3 GPU sent today (a 4gb 680, i was so close to getting the gigabyte SOC but wanted the extra vram).
Looking forwards to running full gen3 system. Thanks again, Gigabyte. : )