It depends on what you call overclocking. For any serious overclocking on the pre-BGA notebook CPUs only an Extreme CPU (XM and MX) can achieve any level of meaningful overclock. The rest of them are gimped just like the mickey mouse BGA K-joke filth, or even worse. The non-XM/MX CPUs are only good for a minor bump, like 400MHz or less, and they do not have fully unlocked power limits. Hardly worth writing home about.