i5 3570k is a BEAST.

[cluthz]

I have a Z77-DS3H and I also have very limited over clocking settings, however I can set multiplier to at least 46 (not tried higher)
Have you checked under advanced voltage settings?

Also how high can u set boost clocks? I've recently started to only overclock boost clocks, as long as cooling is sufficient the machine should use boost at all times it needs it. I did some extensive bench testing on my rig, and all results was within margin of error, so i run x34 on cpu and boost 44/44/44/43 and this should get same speeds in dolphin as a locked multi at x44