
Rate Adaptive Processing inside Routers 195
Normal voltage and
frequency
half voltage and half frequency
zero voltage and
frequency
1/2 of the normal energy
1/8 of the normal energy
(a) work half of the time and sleep half of the time interval
(b) processing is stretched to the whole time interval
Figure 7.4: Benefits of DVFS on energy savings.
significant leverage on energy savings, it may degrade the system performance
due to the decrease of clock frequency. If one could recognize the periods
when absolute guarantees or stringent requirements of network performance
are not required, the energy can be greatly saved by reducing the voltage and
frequency. Po ...