A Brief Tutorial on Power Management in Computer Systems

A Brief Tutorial on Power Management in Computer SystemsDavid Chalupsky, Emily Qi, & Ilango Ganga Intel Corporation March 13, 2007Objective & AgendaObjective:• Establish a common foundation for EEESG work by providing an overview and history of PC power management and LAN use in that context.Agenda:• High Level overview of PC power management– Links to additional information• How Ethernet is utilized in Contemporary PC Power Management• Making Power Management and Ethernet more effective in the future2 March 11, 2007 File: chalupsky_01_0307PC Power States circa 1990• ON• OFFSounds nice & simple. What’s wrong with that?• Time to boot the PC from a cold start took too long, and got longer as PCs became more complex.• As a result, people left their PCs on all the time, wasting energy.3 March 11, 2007 File: chalupsky_01_0307Historical (1990’s) Motivation for Power Managementby market segmentLaptops & Battery Powered Devices– Battery Life is a key product feature, thus– Commercial incentive has always been there– Vendor-specific solutions preceded standardsDesktop PCs– Little end user benefit perceived for PM. – Initial attention to PM in 1992 with the release of EPA’s Energy Star program and international counterparts.Server Systems– Historically, a very performance oriented segment– Always on & ready for maximum performance– Recent, market-driven, attention to power due to high cost of electricity & cooling in Data Centers– EPA ...