حوسبة خضراء

حوسبة خضراء أو تقنية المعلومات الخضراء Green computing, refers to environmentally sustainable computing or IT. In the article Harnessing Green IT: Principles and Practices, San Murugesan defines the field of green computing as "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."[1] The goals of green computing are similar to green chemistry; reduce the use of hazardous materials, maximize energy efficiency during the product's lifetime, and promote the recyclability or biodegradability of defunct products and factory waste. Research continues into key areas such as making the use of computers as energy-efficient as possible, and designing algorithms and systems for efficiency-related computer technologies.

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في العام 1992 قامت وكالة حماية البيئة في الولايات المتحدة الامريكية بإطلاق برنامج Energy Star الذي كان هو عبارة عن شعار يوضع لتمييز الشاشات Screens التي تعمل بكفاءة وفق النظم والمعايير التي وضعتها الوكالة للتقليل من استهلاك الطاقة الكهربائية . هذا الامر ادى الى تبني العديد من شركات تصنيع الشاشات تقنية sleep mode اي وضع النوم الذي يقلل من استهلاك الكهرباء في حالات خمول الجهاز .

شعار Energy Star الذي يمكن ان تجده غالباً عند بداية إقلاع الجهاز

ان مصطلح الحوسبة الخضراء تمت صياغته بعد فترة قصيرة من بدء إنطلاق برنامج Energy Star . كان هناك العديد من المقالات على شبكة USENET (والتي تعني الانترنت في ذلك الوقت )تشرح تلك التقنية [2] وتزامن انطلاق ذلك البرنامج مع انطلاق برنامج آخر يدعى TCO Certification من قبل شركة سويدية تدعى TCO . هدف البرنامج الى دراسة الانبعاثات الإلكترونية في شاشات CRT والعمل على تطويرها وذلك بتقليل الطاقة المستهلكة . توسع هذا البرنامج فيما بعد ليتضمن معايير عديدة : كاستهلاك الطاقة ,ومعيارergonomics , ومعيار استعمال المواد الخطرة في الابنية [3]

Regulations and industry initiatives

The Organisation for Economic Co-operation and Development (OECD) has published a survey of over 90 government and industry initiatives on "Green ICTs", i.e. information and communication technologies, the environment and climate change. The report concludes that initiatives tend to concentrate on the greening ICTs themselves rather than on their actual implementation to tackle global warming and environmental degradation. In general, only 20% of initiatives have measurable targets, with government programs tending to include targets more frequently than business associations.[4]

Energy Star logo.svg


Many governmental agencies have continued to implement standards and regulations that encourage green computing. The Energy Star program was revised in October 2006 to include stricter efficiency requirements for computer equipment, along with a tiered ranking system for approved products.[5][6]

Some efforts place responsibility on the manufacturer to dispose of the equipment themselves after it is no longer needed; this is called the extended producer responsibility model. The European Union's directives 2002/95/EC (Restriction of Hazardous Substances Directive), on the reduction of hazardous substances, and 2002/96/EC (Waste Electrical and Electronic Equipment Directive) on waste electrical and electronic equipment required the substitution of heavy metals and flame retardants like Polybrominated biphenyl and Polybrominated diphenyl ethers in all electronic equipment put on the market starting on July 1, 2006. The directives placed responsibility on manufacturers for the gathering and recycling of old equipment.[7]

There are currently 26 US States that have established state-wide recycling programs for obsolete computers and consumer electronics equipment.[8] The statutes either impose an "advance recovery fee" for each unit sold at retail, or require the manufacturers to reclaim the equipment at disposal.


  • Climate Savers Computing Initiative (CSCI) is an effort to reduce the electric power consumption of PCs in active and inactive states.[9] The CSCI provides a catalog of green products from its member organizations, and information for reducing PC power consumption. It was started on 2007-06-12. The name stems from the World Wildlife Fund's Climate Savers program, which was launched in 1999.[10] The WWF is also a member of the Computing Initiative.[9]
  • The Green Electronics Council offers the Electronic Products Environmental Assessment Tool (EPEAT) to assist in the purchase of "green" computing systems. The Council evaluates computing equipment on 28 criteria that measure a product's efficiency and sustainability attributes. On 2007-01-24, President George W. Bush issued Executive Order 13423, which requires all United States Federal agencies to use EPEAT when purchasing computer systems.[11][12]
  • The Green Grid is a global consortium dedicated to advancing energy efficiency in data centers and business computing ecosystems. It was founded in February 2007 by several key companies in the industry – AMD, APC, Dell, HP, IBM, Intel, Microsoft, Rackable Systems, SprayCool, Sun Microsystems and VMware. The Green Grid has since grown to hundreds of members, including end users and government organizations, all focused on improving data center efficiency.
  • The Green500 list rates supercomputers by energy efficiency (megaflops/watt, encouraging a focus on efficiency rather than absolute performance.
  • Green Comm Challenge is an organization that promotes the development of energy conservation technology and practices in the field of Information and Communications Technology (ICT). Green Comm Challenge achieved worldwide notoriety in 2007, when it enlisted as one of the challengers in the 33rd edition of the America's Cup, an effort meant to show how researchers, technologists and entrepreneurs from around the world can be brought together by an exciting vision: building the ultimate renewable energy machine, a competitive America’s Cup boat.

Approaches to green computing

In the article Harnessing Green IT: Principles and Practices, San Murugesan defines the field of green computing as "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."[1] Murugesan lays out four paths along which he believes the environmental affects of computing should be addressed:[1] Green use, green disposal, green design, and green manufacturing.

Modern IT systems rely upon a complicated mix of people, networks and hardware; as such, a green computing initiative must cover all of these areas as well. A solution may also need to address end user satisfaction, management restructuring, regulatory compliance, and return on investment (ROI). There are also considerable fiscal motivations for companies to take control of their own power consumption; "of the power management tools available, one of the most powerful may still be simple, plain, common sense."[13]

Product longevity

Gartner maintains that the PC manufacturing process accounts for 70 % of the natural resources used in the life cycle of a PC.[14]. Therefore, the biggest contribution to green computing usually is to prolong the equipment's lifetime. Another report from Gartner recommends to "Look for product longevity, including upgradability and modularity." [15] For instance, manufacturing a new PC makes a far bigger ecological footprint than manufacturing a new RAM module to upgrade an existing one, a common upgrade that saves the user having to purchase a new computer.[بحاجة لمصدر]

خوارزميات خضراء

إن تأثير الخوارزميات على عدد الموارد التي يحتاجها الحاسب لإنجاز العمل المطلوب الأثر الكبير في تقليل استهلاك الطاقة بحيث الخوارزميات المتطلبة كالخوارزميات الأسية تتطلب موارد كبيرة لتنفيذها بوقت قياسي . بما ان موارد الحاسب تطورت بشكل كبير وانخفضت اسعار القطع الإلكترونية الخاصة به , امست مسألة فعالية الطاقة والتأثير البيئي لأنظمة الحساب وبرامجه تلقى الانتباه المتزايد .

لقد قام Alex Wissner-Gross وهو فيزيائي في هارفرد بعمل دراسة قدر ان وسطي عمليات البحث في غوغل تنتج 7 غرامات من غاز ثنائي أكسيد الكربون (CO₂). [16] بكل الاحوال شركة غوغل على الرغم من تلك الدراسة مازلات تجادل بأن البحث الواحد ينتج حوال 0.2 غرام من غاز co2 [17]

Resource allocation

Algorithms can also be used to route data to data centers where electricity is less expensive. Researchers from MIT, Carnegie Mellon University, and Akamai have tested an energy allocation algorithm that successfully routes traffic to the location with the cheapest energy costs. The researchers project up to a 40 percent savings on energy costs if their proposed algorithm were to be deployed. Strictly speaking, this approach does not actually reduce the amount of energy being used; it only reduces the cost to the company using it. However, a similar strategy could be used to direct traffic to rely on energy that is produced in a more environmentally friendly or efficient way. A similar approach has also been used to cut energy usage by routing traffic away from data centers experiencing warm weather; this allows computers to be shut down to avoid using air conditioning.[18]


Computer virtualization refers to the abstraction of computer resources, such as the process of running two or more logical computer systems on one set of physical hardware. The concept originated with the IBM mainframe operating systems of the 1960s, but was commercialized for x86-compatible computers only in the 1990s. With virtualization, a system administrator could combine several physical systems into virtual machines on one single, powerful system, thereby unplugging the original hardware and reducing power and cooling consumption. Several commercial companies and open-source projects now offer software packages to enable a transition to virtual computing. Intel Corporation and AMD have also built proprietary virtualization enhancements to the x86 instruction set into each of their CPU product lines, in order to facilitate virtualized computing.

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Terminal servers

Terminal servers have also been used in green computing. When using the system, users at a terminal connect to a central server; all of the actual computing is done on the server, but the end user experiences the operating system on the terminal. These can be combined with thin clients, which use up to 1/8 the amount of energy of a normal workstation, resulting in a decrease of energy costs and consumption.[بحاجة لمصدر] There has been an increase in using terminal services with thin clients to create virtual labs. Examples of terminal server software include Terminal Services for Windows and the Linux Terminal Server Project (LTSP) for the Linux operating system.

ادارة الطاقة

إن مصطلح Advanced Configuration and Power Interface (ACPI) يمثل المعايير الصناعية لاي قطعة إلكترونية يتم صنعها للحاسب هذا المعيار يسمح لنظام التشغيل بان يتحكم بعمليات معينة تؤدي الى تقليل استهلاك هذه القطعة الإلكترونية . يسمح هذا المعيار للانظمة بإطفا بعض المكونات الالكترونية كما في شاشات الحاسب , القرص الصلب بعد فترة من الخمول وعدم العمل . بالإضافة يمكن للنظام ان يقوم بعمل سبات hibernate حيث تكون معظم القطع بما فيها الحاسب والذاكرة Ram مطفأة .

ان معايير ACPI هي الخليف لمعيار إنتل-مايكروسوفت الذي يدعى Advanced Power Management الذي يسمح لل BIOS للتحكم بالطاقة الكهربائية للقطع[بحاجة لمصدر]

بعض البرامج تسمح للمستخدم بان يعدل من مقدار الفولطية المعطاة للمعالج CPU بشكل يدوي , الامر الذي يؤدي الى تقليل الحرارة المنبعثة منه وتقليل الاستهلاك الكهربائي . هذه العميلة تدعى undervolting . بعض الحواسب تقوم بهذه العميلة بشكل آلي بحيث تعتمد في تحديد متطلبات المعالج للطاقة على حمل العمل . هذه التقنية تدعى SpeedStep في معالجات إنتل و PowerNow وCool'n'Quiet في معالجات AMD وتدعى LongHaul في معالج شركة VIA Technologies

دعم انظمة التشغيل

ان نظام التشغيل ويندوز المهيمن على اجهزة الحواسب الشخصية pc's يوفر بعض الخيارات لإدارة الطاقة للحاسب الشخصي PC power management منذ نظام تشغيل 95 . [19] اولى الخيارات التي قدمها نظام تشغيل ويندوز لإدارة وتخفيف الطاقة هي خاصية الاستعداد stand by التي تقوم بتقليل الطاقة المستهلكة لكل من الرام وشاشة العرض في حال خمول الحاسب وعدم العمل . ظهر فيما بعد خاصية السبات hibernate التي تقوم بتقليل الطاقة للقرص الصلب وتدعم معيار ACPI .

إن نظام تشغيل ويندوز 2000 كان نظام التشغيل الأول في عائلة نظم NT(New Tech) الذي قام بتضمين خيارات إدارة الطاقة. هذا الامر تطلب تغيرات حقيقية على معمارية النظام وتطلب تعريفات جديدة لقطع العتاد الصلب hardware . قام أيضاً ويندوز 2000 بتضمين خاصية Group Policy التي هي تقنية تسمح لمدير النظام بتعديل خيارات النظام.على الرغم من ذلك خيارات الطاقة لم تكن جزءً من تلك الخيارات آنفة الذكر .

.          This is probably because the power management settings design relied upon a connected set of per-user and per-machine binary registry values[20], effectively leaving it up to each user to configure their own power management settings.

This approach, which is not compatible with Windows Group Policy, was repeated in Windows XP. The reasons for this design decision by Microsoft are not known, and it has resulted in heavy criticism[21] Microsoft significantly improved this in Windows Vista[22] by redesigning the power management system to allow basic configuration by Group Policy. The support offered is limited to a single per-computer policy. The most recent release, Windows 7 retains these limitations but does include refinements for more efficient user of operating system timers, processor power management[23][24], and display panel brightness. The most significant change in Windows 7 is in the user experience. The prominence of the default High Performance power plan has been reduced with the aim of encouraging users to save power.

There is a significant market in third-party PC power management software offering features beyond those present in the Windows operating system. Most products offer Active Directory integration and per-user/per-machine settings with the more advanced offering multiple power plans, scheduled power plans, anti-insomnia features and enterprise power usage reporting.

مزود الطاقة Power supply

إن مزودات الطاقة للاجهزة المنزلية Desktop computer power supply او اختصاراً PSUs تولد ما يقارب 70-75 % من الكهرباء بشكل عملي وفعال [25] وينشر باقي الطاقة كحرارة منتشرة حول مزود الطاقة . ظهر معيار صناعي يدعى 80 PLUS الذي لا يسمح لمزودات الطاقة بأن تعمل باقل من 80 % بشكل فعال .امست هذه النماذج الجديدة تستبدل بالقديمة وابتداءً من 20/7/2007 جميع مزودات الطاقة العاملة وفق معيار Energy Star 4.0 الجديد يجب ان تعمل بفعالية 80% [26]


Smaller form factor (e.g. 2.5 inch) hard disk drives often consume less power per gigabyte than physically larger drives.[27][28] Unlike hard disk drives, solid-state drives store data in flash memory or DRAM. With no moving parts, power consumption may be reduced somewhat for low capacity flash based devices.[29][30]

In a recent case study, Fusion-io, manufacturers of the world's fastest Solid State Storage devices, managed to reduce the carbon footprint and operating costs of MySpace data centers by 80% while increasing performance speeds beyond that which had been attainable via multiple hard disk drives in Raid 0.[31][32] In response, MySpace was able to permanently retire several of their servers, including all their heavy-load servers, further reducing their carbon footprint.

As hard drive prices have fallen, storage farms have tended to increase in capacity to make more data available online. This includes archival and backup data that would formerly have been saved on tape or other offline storage. The increase in online storage has increased power consumption. Reducing the power consumed by large storage arrays, while still providing the benefits of online storage, is a subject of ongoing research.[33]

كروت الإظهار

إن وحدة معالجة الغرافيكس GPU غالباً ما تكون المستهلك الاكبر للطاقة في الحاسب [34]. إن اهم الخيارات الخاصة بكرت الاظهار المتعلقة بفعالية الطاقة تتضمن :

  • اختيار معالج رسوميات GPU وفقاً لمعدل الطاقة المستهلكة (الأداء لكل واط )
  • استخدام مخرج الفيديو الخاص باللوحة الام -غالباً اداء منخفض للرسوميات ثلاثية البعد وطاقة اقل .

شاشات العرض

ان شاشات عرض LCD تستعمل عادة تقنيةcold-cathode fluorescent bulb لتوفر الإضاءة اللازمة للعرض. بعض شاشات العرض الأحدث تستعمل مصفوفة من الديودات الباعثة للضوء light-emitting diodes (LEDs) عوضاً عن fluorescent bulb اي مصباح مادة الفلوريسنت , الامر الذي ادى الى تقليص الطاقة والكهرباء المستهلكة من شاشات العرض [35]

Materials recycling

Recycling computing equipment can keep harmful materials such as lead, mercury, and hexavalent chromium out of landfills, and can also replace equipment that otherwise would need to be manufactured, saving further energy and emissions. Computer systems that have outlived their particular function can be re-purposed, or donated to various charities and non-profit organizations[36]. However, many charities have recently imposed minimum system requirements for donated equipment.[37] Additionally, parts from outdated systems may be salvaged and recycled through certain retail outlets[38][39] and municipal or private recycling centers. Computing supplies, such as printer cartridges, paper, and batteries may be recycled as well.[40]

A drawback to many of these schemes is that computers gathered through recycling drives are often shipped to developing countries where environmental standards are less strict than in North America and Europe.[41] The Silicon Valley Toxics Coalition estimates that 80% of the post-consumer e-waste collected for recycling is shipped abroad to countries such as China and Pakistan.[42]

The recycling of old computers raises an important privacy issue. The old storage devices still hold private information, such as emails, passwords and credit card numbers, which can be recovered simply by someone using software that is available freely on the Internet. Deletion of a file does not actually remove the file from the hard drive. Before recycling a computer, users should remove the hard drive, or hard drives if there is more than one, and physically destroy it or store it somewhere safe. There are some authorized hardware recycling companies to whom the computer may be given for recycling, and they typically sign a non-disclosure agreement.[43]

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Teleconferencing and telepresence technologies are often implemented in green computing initiatives. The advantages are many; increased worker satisfaction, reduction of greenhouse gas emissions related to travel, and increased profit margins as a result of lower overhead costs for office space, heat, lighting, etc. The savings are significant; the average annual energy consumption for U.S. office buildings is over 23 kilowatt hours per square foot, with heat, air conditioning and lighting accounting for 70% of all energy consumed.[44] Other related initiatives, such as hotelling, reduce the square footage per employee as workers reserve space only when they need it.[45] Many types of jobs, such as sales, consulting, and field service, integrate well with this technique.

Voice over IP (VoIP) reduces the telephony wiring infrastructure by sharing the existing Ethernet copper. VoIP and phone extension mobility also made hot desking more practical.

انظر أيضا


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  2. ^ قالب:Cite newsgroup
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