Jacob R. Lorch and Alan Jay Smith

EECS Department
University of California, Berkeley
Technical Report No. UCB/CSD-97-961
June 1997

http://www2.eecs.berkeley.edu/Pubs/TechRpts/1997/CSD-97-961.pdf

The utility of a portable computer is critically dependent on the period it can be used while running off the battery. In this paper, we present a study of power consumption in Apple Macintosh computers. We measure the existing power consumption for each system component using built-in measuring tools. Since total power consumption is a function of user workload, we use eight user workload traces to determine power use as observed in practice. Apple currently implements some power-saving features, and the effectiveness of those features is estimated; we find typical power savings of 41-66%. After the use of basic power-saving techniques, we find that the major power users are the backlight (25-26%), the CPU (9-25%), the display (4-17%), the video circuitry (6-10%), and the hard drive (4-9%). We then evaluate possible changes in system hardware and software with regard to the power savings they might offer.

BibTeX citation:

@techreport{Lorch:CSD-97-961,
    Author = {Lorch, Jacob R. and Smith, Alan Jay},
    Title = {Energy Consumption of Apple Macintosh Computers},
    Institution = {EECS Department, University of California, Berkeley},
    Year = {1997},
    Month = {Jun},
    URL = {http://www2.eecs.berkeley.edu/Pubs/TechRpts/1997/5500.html},
    Number = {UCB/CSD-97-961},
    Abstract = {The utility of a portable computer is critically dependent on the period it can be used while running off the battery.  In this paper, we present a study of power consumption in Apple Macintosh computers. We measure the existing power consumption for each system component using built-in measuring tools.  Since total power consumption is a function of user workload, we use eight user workload traces to determine power use as observed in practice.  Apple currently implements some power-saving features, and the effectiveness of those features is estimated; we find typical power savings of 41-66%. After the use of basic power-saving techniques, we find that the major power users are the backlight (25-26%), the CPU (9-25%), the display (4-17%), the video circuitry (6-10%), and the hard drive (4-9%). We then evaluate possible changes in system hardware and software with regard to the power savings they might offer.}
}

EndNote citation:

%0 Report
%A Lorch, Jacob R.
%A Smith, Alan Jay
%T Energy Consumption of Apple Macintosh Computers
%I EECS Department, University of California, Berkeley
%D 1997
%@ UCB/CSD-97-961
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/1997/5500.html
%F Lorch:CSD-97-961