this goes to show that the limt to how high the frequency can go is heat, not the properties of the silicon. back in the 80s when CMOS chips were first being introduced, they used a 5V standard, now it is around 1.2V, a decrease of around a factor of 5. the size of the transistor, however, has decreased by a factor of about 100, meaning the electric field across each transistor that is conducting is 20 times greater, letting the heat monster out.