Sustainable Computing By Robert Bennett Power Saving Modes
Power Saving Modes AKA Low Power Modes Modes that a computer can be put in when not in use to save power. • Three Power Saving Modes: • Sleep • Hibernate • Off
Important Terms • Watt: A measurement unit of how much power an electrical appliance uses at one time • CPU (Central Processing Unit): The chip in a computer which performs all the calculations needed to operate the computer • RAM (Random Access Memory): Memory which holds information on what the user is currently working; requires power to hold information
On • Not a power saving mode • Uses 60-250 Watts • Advantages • Computer ready to use • Programs stay open • No interaction needed • Disadvantages • Wastes 54-244 Watts of power
Sleep • CPU=lower power state, RAM=powered • Uses 1-6 Watts • Advantages • Takes little time to exit • Preservers open programs • Disadvantages • Need to remember to enter
Hibernate • RAM saved on disk • Computer powered off • Uses 0.1 to 5 Watts • Advantages • Preservers open programs • Uses no more power than off • Disadvantages • Takes a long time to exit
Off • Computer powered off • Uses 0.1 to 5 Watts • Advantages • Uses little power • Clears RAM, which prevents crashes • Disadvantages • Doesn't preserve open programs • Takes time to start
Summary There are advantages and disadvantages to all power saving modes. It is important to use one to save power.