The Power Wall (Cont.) 

 Power ∝ ½ × Capacitive load × Voltage2 × Frequency switched

Suppose we have developed new versions of a processor with the characteristics shown in the table:
Version Voltage Clock Rate
Version 1 6 V 0.5 GHz
Version 2 3 V 1.0 GHz

By how much has the capacitive load been changed between versions if the dynamic power has been reduced by 20%?  

The problem today is that further lowering of the voltage appears to make the transistors too leaky. Although there are many expensive ways to cool chips, these techniques are too expensive for desktop computers.
Since computer designers slammed into a power wall, they needed a new way forward. They chose a different way from the way they designed microprocessors for their first 30 years—the switch from uniprocessors to multiprocessors.