Power is the bottle neck right now. We have 16 core processors were each core is capable of 4.7GHz individually. But we can't run all of the cores simultaneously at those speeds because we have trouble with power delivery and especially with dealing with the waste heat that comes with using that much power.
The only way we can really use all that transistor density today is to artificially limit clock speeds to conserve power.
The only way we can really use all that transistor density today is to artificially limit clock speeds to conserve power.