Traditionally, a system's performance was measured in terms of its processing power. However, excessive power consumption by computing systems has now become a matter of concern for most organizations. Cost of operating computing systems often far exceeds cost of purchasing them. Hence, considering total cost of ownership (TCO), a new measure that has become popular for measuring performance of computing systems is power consumption to processing power ratio.
Manufacturers of computing systems have therefore made attempts at all levels in computer architecture to reduce power consumption of systems. Processor manufacturers have come out with new processor architectures to reduce power consumption right at processor level. For example, the latest Intel Xeon processor offers a technology called Demand Based Switching (DBS) for reached power consumption. A traditional processor operates only at a single frequency and voltage, regardless of its workload.
Therefore, it is always ON and always consumes full power. Processors based on DBS technology are designed to run at multiple frequency and voltage settings. In conjunction with an Operating System (OS) and Basic Input Output System (BIOS) that support DBS, such processors automatically switch to and operate at the lowest setting that is consistent with optimal application performance. The OS monitors processor utilization multiple times per second and down-shifted/up-shifts to a lower/ higher frequency and voltage as appropriate. Therefore, power usage is automatically tailored to match dynamically changing system workload, which substantially reduces power wastage with minimal impact on peak performance capabilities of the processor.