Once we hit the wall of general CPU performance we will probably retrace a lot of old school custom hardware design. Expect a lot of the parts integrated into a CPU today to move back out, but simultaneously we will have to start shipping more sophisticated cooling solutions for denser CPU chips (since the main reason bridges were integrated were because dense cores were getting too hot for copper / aluminum fin heat transfer like most heatsinks).

It will take a really long time to actually squeeze out CPU optimization. We are still contending with most software not even properly scaling to four cores, let alone well implemented job queue systems for arbitrarily scaled cores. And once the chips start dropping in price as the node standardizes and companies can lay off the intense R&D investments, we can start introducing more heterogeneous compute clusters to drive performance cheaper even when the silicon itself is stuck until graphene takes the market.