Speed now & then

Chuck Guzis wrote on Wed, 11 Apr 2018 11:09:23 -0700 That is correct. The observation that transistors would be faster and use less power as they became smaller is called "Dennard scaling" from 1974: https://en.wikipedia.org/wiki/Dennard_scaling This led to the MHz wars of the 1990s. Sadly, as the isolation barriers (the "O" in "MOS") became thinner and thinner we could no longer ignore leakage currents. In addition, going with lower voltages no longer was possible as we got closer and closer to the transistor threashold voltages. So we got stuck at 3 GHz or less. Besides getting more performance with smaller transistors, we have also been increasing performance by taking advantage of more transistors by doing more stuff in parallel. So we went from up to dozens of clock cycles per instructions to three or four instructions per clock cycle. Quite a few of the additional transistors have been use for more and more layers of caches. -- Jecel