Managing the Impact of Increasing Microprocessor Power Consumption

Abstract

The power dissipation of modern processors has been rapidly increasing along with increasing transistor count and clock frequencies. At the same time, there is a growing disparity between the maximum power consumption of a processor and the “typical” power consumed by that processor; i.e., power consumed while running typical applications. This trend is the result of the significant increase in transistor count required to reach the desired peak performance targets. Designing a processor with the intent of minimizing system costs, especially those arising from high power consumption, while retaining a high level of reliability requires attention at all stages of the design. In the case of the Pentium 4 processor, the design team focused from the beginning on reducing power consumption without negatively impacting either the performance or reliability of the processor in any significant way. Many techniques, both innovative and pre-existing, were applied across the entire processor in an effort to eliminate unnecessary power consumption. The mass adoption of these techniques resulted in a significant reduction in both maximum and typical processor power dissipation.