Hey, I take it you have been using in windows overclocking tools? (Sorry I don't know the Gigabyte app name). Have you ventured into the bios at all?
I dunno if people agree with me, as I am new to I5's as well, but mostly BLCK is like your oldschool FSB this will increase the speed from the memory to the CPU and also increase the CPU speed. Increase the BLCK but watch your voltages, maybe stick the cpu volt in as 1.3 so it doesn't move.
Get to your overclocking speed eg 3.6 and then run intel burn test or prim95 to make sure it is stable. Do this for 2 hours min and if stable increase BLCK or reduce volts but only one at a time and repeat.
Yes it is time consuming but gives you something to do.