def fib(i, current = 0, next = 1):
if i == 0:
return fib(i - 1, next, current + next)
A gate length of 1 µm limits the upper frequency to about 5 GHz, 0.2 µm to about 30 GHz.
While higher frequency is great for improving CPU performance, it is not always the best choice. For example, GPUs tend to rely on a huge number of more efficient transistors and run about 2-4X slower than a CPU. For scenarios where active power is most critical, the 22nm process can keep the same frequency but lower the operating voltage (e.g. from 1V to 0.8V). Active power falls even faster since P ~ F * V2 and Intel claims 50% less power, so the voltage reduction may be slightly larger in some circumstance. Similarly, transistors could use this headroom to significantly lower leakage power for always-on circuits, instead of changing frequency or active power. While Intel did not cite any specific numbers, it seems likely that an improvement of 1-2 orders of magnitude is realistic given the exponential relationship between leakage and drive currents.