Electrical Engineering
      and Computer Sciences

Electrical Engineering and Computer Sciences

COLLEGE OF ENGINEERING

UC Berkeley

Energy Consumption of Apple Macintosh Computers

Jacob R. Lorch and Alan Jay Smith

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

http://www.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://www.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://www.eecs.berkeley.edu/Pubs/TechRpts/1997/5500.html
%F Lorch:CSD-97-961