Power Management in Green Computing
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This document discusses power management techniques in green computing. It begins with an introduction to the Advanced Configuration and Power Interface (ACPI) standard, which allows an operating system to control hardware power savings features. It then discusses power supply efficiency and opportunities to optimize power usage in I/O devices, storage, processors, and operating systems. Specific examples are given around monitor power consumption based on brightness, contrast and display type. Testing showed processor power consumption differences between idle and peak loads were smaller than for graphics cards. The document concludes that power management has significant scope through optimized usage of processors and displays via the operating system.
Power Management in Green Computing
- 1. POWER MANAGEMENT IN GREEN COMPUTING By: Mukund Mudakavi SDM College of Engineering and Technology
- 2. ABSTRACT: Green computing or green IT, refers to environmentally sustainable computing or IT. It is "the study and practice of designing, manufacturing, using, and disposing of computers, servers, and associated subsystems—such as monitors, printers, storage devices, and networking and communications systems—efficiently and effectively with minimal or no impact on the environment.
- 3. 1. Introduction to Power management : The Advanced Configuration and Power Interface (ACPI), an open industry standard, allows an operating system to directly control the power saving aspects of its underlying hardware. This allows a system to automatically turn off components such as monitors and hard drives after set periods of inactivity
- 4. 2. Power supply : Desktop computer power supplies (PSUs) are generally 70–75% efficient, dissipating the remaining energy as heat. An industry initiative called 80 PLUS certifies PSUs that are at least 80% efficient; typically these models are drop-in replacements for older, less efficient PSUs of the same form factor . As of July 20, 2007, all new Energy Star 4.0-certified desktop PSUs must be at least 80% efficient.
- 5. Power Savings Opportunities : Following areas where the authors felt that there is scope of optimising the usage of power I/O devices Storage units Processors Operating Systems Due to their frequency of operation in any computing devices.
- 6. As illustrated below, today’s average desktop computer with a cathode ray tube (CRT) monitor uses more than five times as much energy as a laptop (570 kWh/yr vs. 100 kWh/yr). Therefore, replacing a desktop system with a laptop system could save about 470 kWh/yr - nearly $40 annually. Monitor choice greatly impacts the overall system energy usage. For example, simply switching from a CRT to the increasingly common LCD (liquid crystal display), yields the desktop computer user savings of more than 100 kWh/yr. Likewise, much of the energy savings potential from a laptop is negated if it is connected to an external CRT monitor.
- 8. 2.1 Display : Brightnes White Grey Black CRT s CRT CRT 100 85 74 63 50 84 67.5 60.5 0 77.7 65 60.0 Brightness Power Consumption (watts) 0 15 50 23 100 28
- 9. Power Consumption CRT Monitor LCD Monitor Parameter Avg. consumption 76 W 20 W Screen color sensitivity Extremely sensitive. Completely insensitive. Consumes lot more power Consumes same power for all (43% more) when displaying colors on screen. white on screen. Brightness setting sensitivity Moderately sensitive. Sensitive. Consumes higher Consumes more power at power for higher brightness higher brightness. Less sensitive. (Almost Completely insensitive. Contrast setting sensitivity insensitive when brightness Consumes same power for all setting is low.) contrast Consumption when turned 2W 0W off from computer power settings
- 10. 3. Processors Processor Power Consumption : Testing power consumption of CPUs is a trickier task than graphics cards. The differences in power consumption between a CPU at idle and a CPU at full load wasn't as large as with graphics cards. So it is reported that the difference in idle and peak scores. The systems all had the following common components . . . .
- 11. COMPONENT MODEL Power supply PC power and cooling Turbocool 850 SSI Motherboard, Intel Testing Intel D975XBX Motherboard, AMD testing ASUS A8N32-SLI Memory, AMD testing 1GB Corsair XMS 3200XL, CAS 2-2-2-5 Memory, Intel testing Corsair XMS5300 Pro at 4-4-4-8 Graphics card Nvidia GeForce 7800 GTX (256MB) Hard drive 1 Seagate 7200.8 160GB SATA Hard drive 2 Western Digital 400GB SATA Optical drive Sony multiformat DVD burner
- 12. Operating system issues Linux vs. Windows Power Usage In our "desktop usage" power tests, both Fedora 8 Test 3 and Ubuntu 7.10 had consumed more power than both versions of Microsoft Windows tested. Fedora and Ubuntu were consuming 65 Watts while Windows XP had only consumed 58 Watts and Windows Vista was in the middle with 62 Watts. Granted, this test isn't very controlled and was just intended to give a rough overview.
- 14. 3. Conclusion : It has been observed that the power management can be achieved by controlling the use of the processor through the optimized usage of processer and the display devices through the operating system. A little optimization in the discussed areas will produce the better power control for domestic and commercial computing devices. The power management has a large scope in the portable devices also as it is the technology of the future.
- 15. 4. REFERENCES : San Murugesan, ―Harnessing Green IT: Principles and Practices,‖ IEEE IT Professional, January-February 2008, pp 24-33 http://technet.microsoft.com/en- us/windows/dd361745.aspx). www.Internetworldstats.com for 2005 computer usage statistics www.Industcards.com for 2005 coal fired plants data US EPA Energy information administration EGRID 2000 database as referred by www.greenmountain.com US EPA National Vehicle and Fuel Emissions Laboratory EPA420-F-97-037 standards as referred by www.greenmountain.com http://www.energystar.gov/index.cfm?c=pm_mmd.pr_p m_mmd AMD’s New Phenom Chips to Consume 45W – Sources by Anton Shilov
- 16. THANK YOU