Where we are Going: Heirloom Laptops Below is a plot of Intel CPU clock speed at introduction versus time. There is an abrupt plateau in 2003 where clock speed stopped increasing. Since then, CPU makers have been using multi-core technology to drive performance (effective performance extrapolated as the pink dashed line), but this wasn’t by choice: certain physical limits were reached that prevented practical clock scaling (primarily related to power and wire delay scaling).