Software computation and data manipulation is the essence of the work done on a server and in a datacenter. What is often overlooked is the critical role operating systems play in determining both the performance (the speed of work) and the cost (the energy consumed) doing that work. Operating systems manage a software work plan; an efficient work plan gets work done faster and at lower cost.
Well-optimized operating systems can increase the time spent in low-power CPU, memory, and interconnect states. They avoid careless use of system resources that can limit a server’s use of low-power states—for example, polling ...