Have heard of it happening, not seen it personally. God knows what, the general degredation (at stock speeds/volts) could have been a sign of something not quite right with the core, guess whatever it is might have eventually shorted so bad it caused a high current blowout or something, without vast technical knowledge and an electron microscope no one can be sure and its just wild speculation on my part. My supplier and me have a fairly good relationship as i've used his company for about 10 yrs and have friends in common, get massive discounts etc.. so i doubt hes b'sin me. Already picked up the replacement 2600k, he will deal with the rest. Probably a one in a million chip tbh, lucky me!