Monitor power management (MPM) places monitors into a low-power sleep mode after a period of inactivity and can lead to annual savings of $10 to $30 per monitor. Because it does not affect the computer (CPU, hard drive, etc.), problems associated with activating MPM are exceptionally rare. As a result, IT professionals generally regard MPM as a “no-brainer.” Fortune 500 IT departments typically require less than a day or two to assess, test, and begin rolling out a solution that activates MPM features. Some of the largest companies in the world have activated MPM. See case studies and list of contributors to the ENERGY STAR Million Monitor Drive campaign.
Computer power management (CPM) places computers (CPU, hard drive, etc.) into a low-power sleep mode after a period of inactivity and can lead to annual savings of $15 to $45 per desktop computer. Originally designed to conserve battery life on stand-alone laptops, CPM features, such as system standby and hibernate1, are increasingly deployed to save electricity on desktops.
However, utilizing CPM features in networked environments is not as straightforward as MPM. It is important to ensure that sleeping computers do not interfere with the distribution of administrative software updates. In addition, older software applications and some peripheral devices may not conform to CPM standards, and should be tested for compatibility with CPM.
That said, CPM works well in certain networked environments, especially those where: 1) most PCs have Pentium IV (or newer) processors and run Windows 2000 or XP, and 2) one of the following statements is true:
In addition, free administrative tools for managing CPM settings, such as EZ GPO, have recently become available. Consequently, more and more IT administrators are activating CPM to save money. In fact, Dell now ships its business line of computers with CPM activated. Read about other organizations that have activated CPM.
EPA offers free technical advice to safely activate CPM on your networks.
Some software programs, particularly older applications, do not conform to the latest Advanced Configuration & Power Interface specification and can conflict with CPM. Other types of software and devices may keep the CPU running at a low level of activity, and thus, may not allow the computer to enter a sleep mode. Certain peripheral devices, with incorrectly designed or implemented drivers, can also render CPM inoperable. EPA recommends that IT administrators test peripherals and software to ensure compatibility with CPM.
Given growing concerns about security, more companies are distributing software patches and updates at night, and thus require that machines be left on all night. If machines are in sleep mode, they could potentially be awakened using a feature called wake-on-local-area-network (WOL). However, remote activation and management of WOL features is not possible in Windows environments at this time. As a result, WOL features must be either 1) activated when PCs are imaged — prior to rollout, or 2) activated manually on each machine.
1 System standby (also know as “S3” sleep state) and hibernate (also known as “S4” sleep state) both enter a low-power sleep state (1–3 watts). System standby wakes up faster than hibernate (5 to 10 seconds compared to 20+ seconds) but does not save work in the event of power loss (since it saves work to RAM while Hibernate saves it to hard disk.)
Step 1: Estimate your savings and view case studies.
Step 2: Decide which is right for you: monitor only or both monitor and computer.
Step 3: Evaluate software options and choose a power management method.
Step 4: Inform employees with free educational materials.
Step 5: Activate power management. EPA provides free technical support.
Step 6: Earn public recognition through the Million Monitor Drive campaign.