Computer Power Utilization and Security Guidelines
Reducing Computer Equipment Power Use
As part of the University energy conservation efforts, the UI Energy Council has requested that everyone reduce energy consumption on campus. Specifically the Council suggests “Turning off your computers and any other office equipment when you're not using them, especially overnight and weekends.” For information about the University effort, please read their web page: http://www.facilities.uiowa.edu/energy/index.html
Computer Equipment in the College
Most of the computers in the College are 4 years old or less. Newer computers are designed with energy savings in mind. Below are details of the power use by monitors and computers in the College.
Monitors
Our power testing found that for computer hardware in the college, the computer’s monitor does not draw more power then the CPU. When turned on, a Engineering CRT monitor typically uses 88 watts and an LCD monitor uses 36 watts. In comparison, the typical COE computer uses 110 watts.
Further, the typical CRT power usage in sleep mode is 3 watts and the typical LCD power usage in sleep mode is 1 watt. The power utilization for both the CRT and the LCD monitors are the same in the off state as when they are in the sleep state. The only way to reduce monitor power consumption to 0 is to unplug the power cords, but that has a negative effect on the lifetime of the monitor.
CPUs
The newer CPUs draw about 1 amp, which is about 110 watts of power.
Why Leave Computer Equipment On
Although turning equipment off does save on energy consumption, the wear and tear on the mechanical components can shorten the life of the equipment. Based on the energy drawn and the wear on the equipment, CSS configures Windows computers with the following settings, which the user can change. Go to Start | Control Panel | Power Options
Turn off monitor: After 20 minutes
Turn off hard disks: Never
System standby: Never
[Hibernate]: not enabled
Monitors in sleep mode, as noted above, draw very little power. Turning off the hard drive frequently can wear out parts of the drive, causing it to fail much sooner than if left alone. With computers in standby or hibernate modes, CSS cannot install patches. See below.
CSS does most of the patching and installing updates on the weekend, but about once a month CSS does critical patches and configuration changes during the week at night. With the greatly increased threat of attack from the Internet, CSS has increased the patching frequency. Because we do these updates over the network, if a computer is turned off, the computer will not be patched and so will be vulnerable to various types of attacks.
Many faculty and staff use their computer remotely from home through remote desktop, which requires the computer to be on.
The Future
CSS is working on options that will enable us
to remotely power on college-administered computers over the
network. When this new ability becomes functional, users will
be able to turn off their office computer because CSS will be
able to turn them on remotely in order to do patching. This
functionality will have to be phased in as it is hardware dependent.
Once again, faculty and staff who want to use remote desktop
from home will need to leave their office computer turned on
for that access.