You have a very good 2500k there. I've only seen one other 2500k/2600k that hit 5GHz on less vcore. Until people can nail down just what a safe 24/7 voltage is for these Sandys, I'd play it a little conservative too. I think we will find out in time about 1.45v is ok for Sandys 24/7 on the right cooling, but for now a little caution won't hurt.