The additional transistors predicted by Moore’s Law are being used not to make individual processors run faster but to increase the number of processors inside a chip. In the long term, Intel envisions hundreds of cores per device.

However, the efficiency of parallel systems declines with each added processor, as cores vie for the same data; there will come a point at which adding an additional core to a chip will actually slow it down. That may well set a practical limit on the multicore strategy long before we start buying hundred-core PCs.