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1210

How is IT Services addressing the need to save energy?

IT Services (ITS) currently supports about 4,500 computers out of the estimated University total of around 6,000.  The ITS-supported computers range from new up to about 5 years old. Over 800 of these computers are in "cluster rooms", and many of these are accessible 24 hours per day.

Computers

The latest computer managed by ITS is the Dell OptiPlex 790 (small form).  It has a 240W high efficiency 90% efficient power supply, and is Energy Star 5.0 compliant with Active PFC.
When idle, the machine consumes 15W. When shut down or hibernated but still connected to the mains, it consumes 0.8W.  If a shut-down or hibernated computer is disconnected from the mains, the only power it consumes is that of its internal rechargeable battery.

Monitors

All machines managed by ITS have flat screen monitors, the latest using LED technology. These typically consume about 25 - 70W when in use, and 0.5 - 1.5W when in Standby.

Computer Energy-Saving Settings

All the computers in the Library, ITS Shawcross and cluster rooms are controlled by power-management software (PowerMan) as follows:

Library

1. After 10 minutes inactivity the computer's monitor goes into Standby mode with a blank screen. You need only move mouse to resume work.
2. After further 10 minutes inactivity, the computer is logged off.
3. After 10 minutes showing the 'login' screen the computer enters sleep/hibernation, according to its built-in capability.

A computer in sleep mode will normally return to operation in 10 seconds after the mouse is moved or a keyboard key is pressed. If a computer has been shut down or hibernated then the power button must be pressed to restart the computer.

The PowerMan system also reawakens clustered computers at set times (currently 5am) in order to perform scheduled tasks such as updates.  Once updates are completed, the computers are returned to sleep/hibernation if not in use.

ITS and PCs cluster rooms have slightly different settings as most are used for teaching.

1. After 10 minutes inactivity the computer's monitor goes into Standby mode.
2. After a further 30 minutes inactivity, the computer is logged off.
3. After 10 minutes showing the 'login' screen the computer enters sleep/hibernation, according to its built-in capability.

The lecture theatre and seminar room PCs have different settings. After 120 minutes of inactivity the computer is logged off but the monitor does not go into Standby during that period. After 15 minutes showing the 'login' screen the computer enters sleep/hibernation, according to its built-in capability.

Other PCs managed by ITS also have power saving built into their configuration. They are set so that a screen saver cuts in after 12-15 minutes (but without power saving), and 5-8 minutes later the monitor switches down into standby (providing a significant power saving).

ITS plans to deploy PowerMan on more staff workstations with flexible settings.

Using Hibernate on a Windows PC

By using Hibernate, you can turn a computer off without having to close down all your applications. 

To hibernate your computer:

1. From the Start menu, choose Shut Down or the power icon
2. Select Hibernate
3. Click OK

The computer will then turn off, after saving its present state. 

When you switch the computer on, it will bring itself back to where you left off. Typically, it will also launch more quickly than if you were starting it after a full shut down.

Further Information

Click on the links below to find out more.

High Efficiency 88% efficient power supplies

Energy Star 5.0 Compliance

Advanced Configuration and Power Interface (ACPI)

Dell Optiplex 760 power consumption