CompTIA's Strata Green IT Certification: Power Usage and Conservation
In earlier articles, we looked at the Strata program from CompTIA and introduced the Green IT certification. We started breaking down the objectives of CompTIA’s Strata Green IT certification exam (number FC0-GR1), with a focus on what you need to know in order to be successful on this exam and earn the certification. The focus of this article is Section 1.2 of the exam: “Identify and implement environmentally sound techniques to preserve power.”
This section centers on the minimization of power usage and conservation of energy throughout the IT department. Using power conservatively and consciously is a fundamental aspect of environmentally-aware IT initiatives, and achieving this task takes the form of a number of diverse techniques and technologies.
Working with the Basic Input-Output System (BIOS) of PCs is most likely not unfamiliar to anyone who has spent some time in the field of IT. Taking full advantage of BIOS settings in order to conserve power and make the performance of a single PC or entire IT department more environmentally sound, however, may be a less comfortable practice for those preparing to take the Green IT exam. The exam’s objectives touch on a number of specific settings within the BIOS interface; let’s take a quick look at some of the most prominent.
- ACPIThe Advanced Configuration and Power Interface (ACPI) serves as a cross-platform standard for power management configurations. While the average computer user is only aware of their computer being “on,” “asleep,” or “off,” IT professionals need to understand the ACPI specifications relating to each of these power usage states. Global power states for ACPI-compliant computers range from G0 to G3.
- Screen BrightnessAdjusting screen brightness within the BIOSas opposed to simply accessing your operating system’s control panel or using controls on the monitor itselfmight seem unnecessary to some. It unveils an important consideration for green IT professionals, however. Letting screen brightness be easily tampered with by members of your organization can lead to convenience taking priority over conservation. When, with a couple clicks, anyone can restore monitors to their brightest, most energy-draining settings, they often will. So, make changes through BIOS to set monitors to conservative but usable brightness levels and do not forget to enable screen dimming after short periods of inactivity.
- Wake on LANEnabling Wake on LAN (WoL) through your BIOS lets you turn on or wake up a computer remotely with what is known as a magic packet. If you’re familiar with the logistics of gaining remote access to multiple computers, this is an excellent way to maximize the time PCs can be powered down without losing access to them. In Windows 7, by default, WoL is enabled for desktop computers and disabled for laptops.
- CPU StatesThe Green IT exam’s objectives list four products used for power management through altered processor states: SpeedStep by Intel, PowerNow! by AMD, VIA Technologies’ LongHaul, and LongRun by Transmeta. Even if you only interact with one of these technologies in your own IT department, it’s important to understand the benefits shared by all four. Each offer the ability to dynamically alter CPU usage to instantly meet the needs of programs in use while minimizing or eliminating unneeded power usage. This dynamic throttling makes these technologies more sophisticated in their green efforts than products that simply switch the CPU between states of low and high power usage.
A PC is in the G0 state when working—the height of its power usage. The G1 state signifies sleeping and is broken down into sub-states S1-S4. While the computer appears off in all sub-states of G1, sequentially less power is used throughout them. The most common state of “sleep” is S3, in which the CPU is powered down but RAM is not. S4 is commonly called “hibernate” mode. Global state G2 signifies “soft off,” where minimal power is used but external device input can return the PC to working mode. In G3, a computer is entirely powered down. The only component still running is the PC’s internal clock. In Windows 7, you can configure a number of things related to power, such as what will happen when you press the power button, with sleep and hibernate being two of the options (see Figure 1).
Figure 1 Inside the Windows 7 power configuration options, you can choose what will occur when the power button is pressed.
Within the BIOS interface, enabling the “ACPI Suspend to RAM” sets the computer’s primary standby mode as ACPI state S3 and allows it to use less power during downtimes than if it remains in G0 or higher G1 sub-states.
Take time to explore the BIOS the equipment in your IT department. Additional power management features, such as fan speed control and on/off timers are available on most PCs. Exploring these features will not only help you be prepare for this section of the exam, but also better equip you to make power-saving changes to daily computing practices.
Operating System Settings
Before touching on some of the power management settings available through your operating system (as opposed to BIOS) it is important to note that OS and BIOS settings can interfere with each other and lead to the slowing-down of your computers and a negating of their power-saving effects. If you experience problems after changing these settings, it is a good idea to completely disable either your OS or BIOS features and make the changes in only one place.
- Basic SettingsThe most basic power management settings are always a good place to start when perusing for how your OS can get greener. In Windows 7, opening the “Power Options” menu from the Control Panel’s “System and Security” tab will let you alter screen brightness and sleep and hibernate timers, as well as battery preferences for notebooks. For Mac users, these options are available in the System Preferences section of the Apple menu. Getting a good grasp of the computing habits and schedules of yourself and your organization allows you to take full advantage of these simple settings and use them most effectively in your green IT strategies. Again, remember that other users have easy access to these settings if administrative locks are not put in place.
- Advanced SettingsOpening up the advanced power management settings in Windows or OSX reveals a number of other tools covered on the Green IT exam. When enabled, the USB Selective Suspend setting instructs the computer to suspend individual USB ports and devices without disabling others (as illustrated in Figure 2). Thus, devices like USB fingerprint scanners use significantly less power from the computer by being suspended until the short periods of time they are needed. Similarly, PCI Express cards are used more efficiently by utilizing operating system settings that move the card to a state of lower power usage when links to it are idle.
Figure 2 You can individually configure the power settings for each device in Windows 7.
Most of the other advanced settings within your OS are self-explanatory; for instance, power settings for search, media sharing, and lid closure on notebooks. Experiment with these features to learn how much power can be saved before performance and usability suffer.
This section of the exam also covers the consolidation of office equipment to minimize power usage (although the benefits of this practice also manifest financially, spatially, and beyond). In recent years, multifunctional devices such as printer-scanner-fax combos have become more common and affordable, and they are a great place to start the process of consolidating office equipment. Even more substantial impacts can be made by implementing thin clientscomputers which rely on the server, rather than internal components, to fully performthroughout the organization and transitioning from desktop PCs to energy-efficient laptops when possible. In general, laptops need less than half as much energy to operate as desktop PCs and monitors. So as long as their use is coupled with environmentally-friendly habits (i.e., unplugging chargers, sending to sleep on lid closure) a switch to laptops is a powerful element of green IT strategies.
When desktop monitors are being used, keep two things in mind: LCD and LED. It’s no secret that LCD monitors use significantly less energy (not to mention desk space) than their cathode-ray tube (CRT) counterparts, but you should also check out what kind of backlight your monitors use. LED backlights, unlike cold cathode fluorescent lamp (CCFL) backlights, are able to illuminate portions of the screen more selectively and need less power to get the job done.
When it comes to hoarding power within a PC, graphics cards take the cake. In fact, powerful cards can end up accounting for more than 50% of the PC’s energy consumption at peak usage. One alternative to the high power consumption of robust video cards is the implementation of thin clients that get rid of the cards entirely and look to shared servers for their video needs. Also, try simply using video capabilities of the motherboard, which are most often less powerful and energy-dependent. If your organization doesn’t need extensive graphics capabilities, get smart and get rid of them.
Power Over Ethernet
Power Over Ethernet (PoE) allows for electric power to be distributed to various devices through the Ethernet cables that already connect them to their respective networks. Use of this technology is regulated by IEEE standard 802.3. Using category 5 Ethernet cable at full loads, up to 25.5 watts of power can be carried to devices such as Voice over IP telephones, routers, and webcams. Optimizing use of PoE can eliminate the power footprint of these small devices and add up to a significant decrease in energy consumption.
Active CPU cooling systems, which use fans or water in addition to passive heat-sinks, are considered the norm of modern computing. This does not mean, however, that exclusively using passive heat-sinks is an obsolete practice, especially in the field of green IT. An energy audit of your IT equipment reveals where more sophisticated cool methods are needed and where they aren’t. Where it’s viable, switch to passive cooling to preserve energy wasted by unnecessary fans.
This completes the discussion of the topics beneath objective 1.2 and should provide you with the information you need to know for this portion of the exam. In the next installment, we will take a detailed analysis of objective 1.3: “Explain the purpose and application of virtualization technology.”