Choose software that allows you to estimate energy savings and payback. You need to collect information about all of the PCs on the network to determine what the best power-management strategy is before you begin an implementation. Some software packages can track the time each computer spends in each operating mode—active, low power, hibernate, or off—and use these data to estimate the energy savings that would result from a range of policies before the network administrator implements any one of them. The reported data can also help the administrator accurately determine energy savings after a policy has been implemented.
Choose software that permits different settings for different users. A one-size-fits-all approach to PC power management will rarely be successful because employees have differing work schedules and ways of using their computers. Ignoring this fact and trying to implement a policy that works for everyone will either be so lenient that it leaves a lot of potential energy savings on the table, or it will be unduly restrictive for some users, negatively affecting their productivity and leaving them frustrated.
Some power-management software packages allow the network administrator to define multiple groups of workstations and to establish different power-management settings for each group. For example, one group might consist of workers who are at their PCs continuously on a regular 9-to-5 schedule. Another group could include factory workers who need to intermittently monitor a production process that runs three shifts per day, and a third group could include staff who monitor real-time data on PC screens but only infrequently use the keyboard or mouse. And if the organization wishes to allow it, another profile could be established for specific employees who would be permitted to opt out of the PC energy-savings program.
Choose software that identifies the hardware and operating system used at each workstation. This information is critical to determining groups of similar machines and identifying machines for which power management is inappropriate. For example, machines running the Windows NT operating system have no low-power modes, and, for some older machines, enabling power management may lead to unacceptable delays when a user needs to “wake up” a computer from a low-power state.
Choose software that can shut computers down. In addition to controlling the amount of idle time after which PCs will enter a low-power state, some software packages can implement a turnoff schedule. In most cases, the shutdown procedure is terminated if any application running on a computer offers an “unsaved data” prompt. The shutdown feature can be used even with PCs running operating systems that are incompatible with power management (such as Windows NT), to ensure that those PCs are not left on overnight or over the weekend.
Consider “wake-on-LAN” capability. This feature can bring a networked computer into the active state from the off state. Wake-on-LAN capability is built into most newer computers, and some software takes advantage of it. Because wake-on-LAN gives network administrators access to any computer at any time, it overcomes one of the most common obstacles to using power-management software: the need to install software patches and updates on networked computers when they aren’t in use.