There will be some exceptions but generally overclocking isn't what it used to be, modern chips are kind of reliant on 'out the box overclocking' via boosting/turbo etc, it's all some big equation around clocks, temps and voltages that gets managed behind the scenes now. To be honest, overclocking nowadays seems to be as much about optimising the parameters that are used for all that stuff, to allow the system to maintain higher clocks for longer. The days of buying a chip with a speed of X and then just going in and setting higher multipliers/FSB with perhaps a tad more vcore are largely behind us.
A by-product of this is that the binning of chips is likely 'more accurate' these days i.e. if your silicon is going to come out well from that equation then it will likely be sold as one of the higher end chips. This suppresses traditional overclocking even more because the oldschool option of just buying a cheap lower clocked part that's probably just been binned that way for market segmentation and setting the clockspeed to that of the flagship often isn't that straightforward.
