Also, I think there are some physical limitations that keep chips below a certain clock speed. Besides, the bet has been on "smarter instead of faster", i.e. pr

Also, I think there are some physical limitations that keep chips below a certain clock speed. Besides, the bet has been on "smarter instead of faster", i.e. producing chips that suit our computing needs, which are more adequately supported by parallel processing. High performance cores are useful for problems that are hard to paralellize, but so far it seems that the breakthrough only occurs when a new approach to the problem makes it feasible on multiprocessing platforms (e.g. graph processing is hard to paralellize due to dependencies among graph nodes, Pregel and similar offer a different approach)...a 50GHz CPU won't save you if you need to process a huge graph (i.e. billions of nodes) on a single thread, it'll always take a lot of time. As to the "record", I think IBM already had a Series Z that is over 5GHz.