How To: Build A Clean, 'Green' Machine

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The whole world, it seems, is "going green." When applied to IT, the term green power generally means conserving energy by limiting the energy consumption of computing gear, as well as minimizing the wasted energy that results from the daily rigors of computing.

Green power also means that a system is environmentally-friendly, both in the construction of computer components, and in their proper disposal, so as to avoid contaminating the environment during manufacture, use, or when components or systems go bye-bye. To merit a green label, system builders or integrated must devise, then execute, a well-documented plan to serve an environmentally-friendly agenda.

In fact, energy conservation is taking a central role in the development of several key computing components. These range from the intense processing of a CPU, to the power supplies that deliver electricity to PC components, and even to the devices used to reproduce text and images on paper. During all of these processes, energy is spent while some is inevitably lost in the form of heat waste.

For some computer components, energy efficiency is measured by the ratio of output energy to input energy. This is often expressed as a percentage that indicates how much of the input electricity the electronic component in question actually gets to put to real work. Thus, if a component is described with 70 percent efficiency, much of the energy it consumes is used; but 30 percent of all the electricity it consumes is wasted, usually in the form of heat, also known as thermal output. In turn, such heat build-up must often be offset by internal and external cooling mechanisms. These mechanisms also serve to increase overall power consumption. Within a densely populated computing environment, this can increase operational costs and shorten hardware life spans.

The Green Power of Energy Star

The need for clean, efficient power consumption has motivated vendors to build Energy Star compliant hardware devices across a broad range of computer component types. Many of these devices feature stand-by modes and power-management capabilities to further reduce energy consumption and operational costs, and to prolong their life spans.

Since its inception in 1990, the Energy Star initiative has inspired a bevy of power conservation features in tested and certified equipment. With an ever-expanding industrial workforce that continues to rely on the computers, energy consumption is bound to keep rising. The sorts of energy-saving techniques that were once exclusive in mobile computing platforms are now finding their ways into Energy Star compliant desktop computers at the forefront of today's IT business infrastructure. The overall objective is establish more environmentally friendly methods of operation that should be beneficial for both computers and end-users alike, a process that must begins with component vendors, and be carried through by those who put computer systems together. Here's a shot of the familiar Energy Star logo:

In this Recipe we'll give you some insight into the following key areas of green components: processors, power supplies, motherboards, disk drives, monitors, printers and fax machines, and copiers and scanners. We'll also cover the multi-function device sometimes called a "hydra" that combines two or more of the four preceding functions (such as a printer/fax/copier) into a single box. Finally, we'll also discuss the Advanced Configuration Power Interface (ACPI), an industry standard specification, whose focus on efficient handling of power and its consumption makes it a natural when it comes to discussing green machines.


We start with our first component on our way toward a green machine, namely, the processor. Many modern processors consume somewhere between 89 to 119 watts of power. When you stop to consider that the surface of a typical CPU die is on the order of between one-quarter- and one-half-inch squared, you can put this in perspective as being hotter than a common clothes iron.

AMD's pioneering concept of performance-per-watt, which seeks to maximize each unit of power. Both the energy-efficient Athlon 64 (in both single and dual-core varieties) and the Sempron budget-line processors are veritable poster-children for conservative power design. Both also facilitate the green-computing concept.

Newer designs draw on fewer watts per part, with some AMD CPUs consuming only 35 to 65 watts nominally, and often less. The latest-generation Intel CPUs consume anywhere from 24 watts to 65 watts. Here's a look at both the AMD Athlon 64 and the Intel Core 2 Duo processors:

Power Supplies

Philips continues to develop its Green Chip family of energy-efficient integrated circuits, starting with the Green Chip PC, a unified design that increases desktop power supply efficiency greater than 80 per cent. The company's patented Green Chip SR is a secondary control IC for notebook adapters that improves the efficiency of laptop power adapters, as well. Using a unique topology, Philips has devised a way to further reduce heat waste by encouraging a power-conservation trend directly at the source.

CoolerMaster eXtreme Power and Real Power series PSUs utilize a green power design to meet both Energy Star operating standards—and are capable of reaching 70 percent energy efficiency during operation. More specifically, the IGreen series PSUs offer advanced efficiencies that reportedly exceed 85 percent efficiency using Double Forward Switching Technology (or DFST). This incorporates an intelligent circuit to monitor and stabilize power output levels, while maintaining at least 80 percent efficiency ratings across its output range.

Seasonic is one of a dozen vendors (including SilverStone) listed among the 80 Plus efficiency certification, an electrical utility-funded incentive program designed to validate energy-efficient power supplies. Among the qualifying candidates, Seasonic dominates the market with 11 certified PSUs, ranging from 300 watts to 650 watts. Seasonic's power supplies also enjoy a reputation as being whisper quiet, as well as exceptionally cool and efficient. Here's a look at the Seasonic power supply:

For more information on related certified products from qualifying vendors, see the listCertified Power Supply Products and Suppliers page provided by the 80 Plus organization.


Green also means reducing the percentage of computer parts that contain lead. One area where this heavy metal can be addressed is in motherboard construction. Historically, chips have been fastened to motherboards using tiny deposits of lead-based solder. More recently, this poisonous and dangerous heavy metal has been effectively replaced by a more environmentally friendly mixture of copper, silver and tin.

In 2004, mothervoard vendor VIA completely eliminated lead from its manufacturing processes to comply with then-new laws governing IT equipment recycling practices. That year, the company announced its first-ever lead-free motherboard, the AS-1210. VIA chipsets and motherboard designs may be found in many different OEM systems and in retail motherboard packages. Since that time, other top-level vendors, including Intel, have also begun to produce lead-free designs. Intel's offerings include the older 915GAVX as well as the newer 945GTPL, 955X, and 975X desktop motherboards.

When it comes to motherboard power consumption, power efficiency is best facilitated by a well laid-out cooling infrastructure. Motherboards such as Gigabyte's K8NF-9-ULTRA feature a fanless nForce4 chipset design. This reduces overall power draw by eliminating a cooling fan that would typically be used to cool key chipsets in other designs. Instead, this offering leverages case design to facilitate cooling. Similar products from Asus, FoxConn, and MSI are also becoming increasingly more available. Gigabyte's K8NF-9-Ultra fanless motherboard design is shown here:

Disk Drives

Many modern disk drives, such as Samsung's SpinPoint series, feature a power-saving mode. Samsung also offers an additional specialized power control method to suspend disk activity during any prolonged idle intervals. When fully supported by the OS, several levels of suspend-to-disk functionality are possible (for more, see the Advanced Power Configuration Interface (ACPI) section below). In fact, the SpinPoint drive depicted below can cut its power consumption to less than 10 percent of normal levels:

While most disk drives offer one or more suspend modes, forthcoming hybrid drive technologies hint at even better power-saving strategies. They will marry the low-power properties of flash storage and the operation of disk hardware. For example, Samsung's Hybrid Hard Drive (HHD), set to debut in 2007, will help extend battery-life for laptop users by as much as an additional half-hour. The drive also promises to improve overall responsiveness during boot-up and restore operations, thanks to larger on-board cache and reduced dependence upon spinning platters to recall recently accessed data. Microsoft is reported to have such technology listed as a requirement for its upcoming Windows Vista operating system.


Most of the heat waste produced by computer components may be attributed to common CRT monitors, with their immense size and component weight, compared with lighter, more energy-friendly LCD displays. Energy Star-compliant monitors can reach low-power states from 15 watts operational to 8 watts after idle periods. They reportedly consume 90 percent less electricity than monitors that lack such power-management capabilities. Viewsonic, to name just one supplier, offers several Energy Star compliant monitors, such as this one:

Screen savers and background tasks tend to interrupt and even prohibit suspend states, so a green PC's power profile should exclude any activity that may prevent a CPU or display from hibernating. For qualifying monitors, see the official Monitors Product List provided by Energy Star (Excel spreadsheet download)..

Printers and Fax Machines

For every printer, there's an individualized energy-usage pattern based on the number and appearance of features that serve a variety of purposes. Energy Star-compliant units throttle power consumption between 10 watts and 100 watts following a predefined period of inactivity—typically from 5 to 90 minutes. Printers certified as Energy Star-compliant are said to use 60 percent less energy than non-compliant devices, according to the U.S. Environmental Protection Agency (EPA). And the majority of ink-jet printers meet certification criteria using inherently energy efficient designs without requiring assistance from power-management regimes.

Larger, more complex (and more energy-consumptive) laser printers typically include such capabilities to help them manage their larger energy budgets equally effectively. For example, Dell's 3100cn model printer is environmentally friendly and visually striking:

For more information, see Energy Star's official Printer, Faxes and Mailing Machines Products List (Excel spreadsheet download).

Copiers and Scanners

Copiers and scanners that lack power-management features can overuse electrical energy that goes largely wasted. Energy Star-compliant scanners may enter sleep modes using only 12 watts of power following 15 minute periods of inactivity. Studies show such regimes can save upwards of 50 percent of the electrical costs associated with similar, but unregulated devices. Canon, to name just one supplier, makes several energy-efficient copier models; here's a look at the company's model C210:

For more information on related compliant products, go to Energy Star's Copiers Product List, as well as their Scanners Product List (Excel spreadsheet download).

There's also a class of machines jokingly called "hydras," after the mythical multiheaded beast, but more properly termed "multifunction devices." These combine the capabilities of printers, faxes, scanners, and sometimes more. Like the other machines mentioned here, they can be prodigious consumers of electricity; this make Energy Star-compliant versions of such multifunction devices every bit as desirable as their single-function counterparts. For more information, go to Energy Star's page on Multifuction Devices.
The Advanced Configuration and Power Interface, or ACPI, is an open industry specification co-developed by Hewlett-Packard, Intel, Microsoft, Phoenix, and Toshiba. ACPI defines several modes of operation that can reduce power consumption and increase operational efficiency for properly designed components. Each component can be placed in varying states of sleep—otherwise called "suspend" or, in some cases, "hibernate"—to make this possible.

In commercializing ACPI, Intel has gone with the trademarked term SpeedStep. AMD uses its own trademarked term, Cool'n'Quiet. Both refer to proprietary but well-intentioned designs to limit power-consumption when systems aren't heavily loaded.

Essentially, each stage of suspend eliminates power to some core component until even the CPU and memory no longer draw power. This flexibility allows for a broad range of power profiles to suit numerous conditions and purposes. It also means that—in exchange for being willing to wait a bit longer to wake back up and return to an active, capable state—users can trade lower power-consumption levels over time for more battery life on mobile devices or to lower their desktop gear electric bills.

The following tables shows ACPI suspend states for processors. Keep in mind that the analogy with ever-deeper levels of sleep is pretty apt: The lower the power consumption goes, the more time and energy it takes to "wake" a system back up to a normal, full-powered and operational state. Delays can range from short fractions of a second in light suspend states to as long as 30 seconds in deep suspend states—even longer when the device is completely turned off.

C0 Fully-operational state (powered on)
C1 Halt; not executing instructions, can reach execution state instantly
C2 Stop-Clock; CPU maintains software-visible state, slower to awaken
C3 Sleep; no cache-coherency but maintains other operational states

The next table describes ACPI suspend states for devices:

D0 Fully-on operational state
D1 Intermediate power state (individually defined)
D2 Intermediate power state (individually defined)
D3 Fully-off non-operational state (unresponsive to its corresponding bus)

By setting specific thresholds of system activity based on CPU load, disk activity, display use, and so forth, these schemes basically instruct systems (or components) when to increase or decrease their power consumption levels. They also instruct systems when to start descending the ladder of suspend states, as described in the two preceding tables, as inactive systems become increasingly inert and unresponsive to user input and activity. These schemes are designed to minimize power consumption. On portable PCs, this has the nice side effect of also extending battery life. On desktop PCs, this offers equally attractive energy savings overall, which is particularly appealing for machines that must be left powered-up at all times.

More Green Tips

Another green option: You can purchase green PCs, such as Computer Technology Link's CTL Meridian SL700, which was released in late 2005. The SL700 reportedly consumes as much as 20 percent less energy than most PCs, operates at low-decibel sound levels, features a lead-free Intel 945GTPL motherboard, and ships with an end-of-life coupon for free recycling services (once the unit falls into disrepair).

Build green PCs by using green parts wherever possible and by choosing best-of-breed components as measured by their electrical efficiency, power-management facilities and environmental friendliness. This must be accompanied by provisions for proper disposal of equipment that has out-served its usefulness. You can instruct clients and users on how to properly dispose of old systems. Even better, include provisions for proper disposal as part of the sale. For more on this topic, see this recent TechBuilder related Recipe Recycle Old Hardware the 'Green' Way.

By deploying energy-efficient and environmentally-friendly components, system builders can do a lot to green-up their builds and upgrades. By switching from energy-hungry CRT displays to more energy-efficient LCD displays, you can green-up things even more. Make sure to take advantage of power-management modes, particularly sleep states and hibernation modes, to lower power consumption to the absolute minimum while PCs are idle. Low-consumption states are not just for laptops anymore!

SIDEBAR: Additional Green Resources

System builders can turn to some great Web sites for more information, product ratings, and reviews on sites that specialize in quiet or green PCs. Here are some recommended resources:

  • Green Office Guide: This U.K. site offers an excellent animated resource on the safe disposal and maintenance of common computing environments.

  • Founded by Mike Chin, this site is dedicated to reviews, news and information about quiet, low noise, and/or silent computers and components, as well as their energy efficiency and thermal performance.

  • Energy Star-compliant computers: Search through the official listings online via pull-down menus, which offer choices of product type, brand and OS.

  • The European Union's Eco-Label for PCs: The Eco-Label program is more stringent than it's U.S.-based counterpart Energy Star. Consequently, the PCs and components listed will be more expensive, but they will be a bit greener.

  • The Electronic Industries Association (EIA): This non-profit consortium lists agencies and corporations that recycle used computing equipment on its consumer education initiative page, and also provides information about potentially toxic materials.

ED TITTEL is a freelance writer and trainer in Austin, Tex., who specializes in Windows topics and tools, especially networking and security related matters. JUSTIN KORELC is a long-time Linux hacker and Windows maven who concentrates on hardware and software security topics. Ed and Justin are also co-authors of Build the Ultimate Home Theater PC (John Wiley, 2005).

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