Green computing is the study and practice of usingcomputing resources efficiently. The primary objective ofsuch a program is to account for the "People, Planet,Profit” to maximize energy efficiency during the productslifetime and promote recyclability or biodegradability ofdefunct products and factory waste.Modern IT systems rely upon a complicated mix of people,networks and hardware as such, a green computinginitiative must be systemic in nature.
In 1992, the US Environmental ProtectionAgency launched “Energy Star”, a voluntarylabeling program which was designed topromote and recognize energy efficiency inmonitors, climate control equipment, andother technologies. This resulted in thewidespread adoption of sleep mode amongconsumers of electronics.The term "green computing" was probablycoined shortly after the “Energy Star“program
As computers play an ever-larger role in our lives, energydemands, costs, and waste are escalating dramatically.• The added heat from inefficient computers can increase thedemand of air conditioners and cooling systems, makingyour computing equipment even more expensive to run.• Even though most of today’s desktop computers arecapable of automatically transitioning to a sleep or hibernatestate when inactive, about 90% of systems have this functiondisabled
Desktop consumption has reached 100 watts Total Personal Computer(400 million) energy usage in 2000 was 26 nuclear power plants Power is the bottleneck of improving the system performance Water Cooled Computer Power consumption is causing serious problems because of 5
Nuclear 1000 ReactorPower Density (W/cm2) Pentium 4 Hot Pentium 3 100 Plate Pentium 2 Pentium Pro Pentium 10 486 386 1 1980 1990 2000 2010
In order to achieve sustainable computing, we need torethink from a “Green Computing” perspective,because :Green Computing: *Maximize energy efficiency *Reduce of the use of hazardous materials such as lead *Maximize recyclability of both a defunct product and of any factory waste
• Understand all levels of the computer• Understand where power is dissipated• Think about ways to reduce power usage at all levels
THE 6 LEVELS OF A COMPUTER 5 High Level Programming 4 Assembly Language Software 3 Operating System 2 Instruction Set Architecture 1 Digital Logic Hardware 0 Integrated Circuit8 9
• An average desktop computer requires 85 watts just to beidle, even with the monitor off. If that computer were in use oridling for only 40 hours a week instead of a full 168, over $40in energy costs would be saved annually.• If each household in a region the size of the metro Bostonarea turned off its computer for just one additional hour perday, it would save $3.2 million in electricity costs and prevent19,000 tons of CO2 from heating the atmosphere.• Electricity production is the largest source of greenhousegas emissions in the United States, ahead of transportation.
“The performance of software systems isdramatically affected by how well softwaredesigners understand the basic hardwaretechnologies at work in a system. Similarly, hardware designers must understandthe far-reaching effects their design decisionshave on software applications”
Our computer’s SLEEP and HIBERNATE settings are two of the mosteffective ways to make our computer more environmentally friendly.SLEEP MODESleep mode conserves energy by cutting off power to our display, harddrive,and peripherals. After a pre-set period of inactivity, our computerswitches to a low power state. .HIBERNATE MODEHibernate mode saves energy and protects our work by copying systemdata to areserved area on our hard drive and then completely turning off ourcomputer. It also reduces wear and tear on our components. When weturn power back on,our files and documents appear on our desktop just as we left them.
• AlgorithmicEfficiency• Power Management• Video Card• Display• Materials Recycling• Telecommuting
The efficiency of algorithms has an impact on the amount ofcomputer resources required for any given computing functionand there are many efficiency trade-offs in writing programs.As computers have become more numerous and the cost ofhardware has declined relative to the cost of energy, the energyefficiency and environmental impact of computing systemsand programs has received increased attention
The Advanced Configuration and Power Interface (ACPI), anopen industry standard, allows an operating system to directlycontrol the power saving aspects of its underlying hardware.This allows a system to automatically turn off componentssuch as monitors and hard drives after set periods of inactivity.In addition, a system may hibernate, where most components(including the CPU and the system RAM) are turned off.
A fast CPU may be the largest power consumer in a computer.Energy-efficient display options include:•No video card - use a shared terminal, shared thin client ,or desktop sharing software if display required.•Use motherboard video output - typically low 3Dperformance and low power.•Select a GPU based on low idle power, average wattage,or performance per watt.
CRT monitors typically use more power than LCDmonitors. They also contain significant amounts oflead. LCD monitors typically use a cold-cathodefluorescent bulb to provide light for the display.
The recycling of old computers raises an importantprivacy issue. The old storage devices still hold privateinformation, such as emails, passwords, and creditcard numbers, which can be recovered simply bysomeones using software available freely on theInternet.
Teleconferencing and telepresence technologies areoften implemented in green computing initiatives. Theadvantages are many:• Increased worker satisfaction,•Reduction of greenhouse gas emissions related totravel,•Increased profit margins as a result of lower overheadcosts for office space, heat, lighting, etc.
• Turn off the computer when not in use, even ifjust for an hour.• Turn off the monitor when not in use (asopposed to running a screen saver).• Use power saver mode.• Use hardware/software with the Energy Starlabel.• Don’t print unless necessary.• Use LCDs instead of CRTs as they are morepower efficient.