Power-Saving for £0 Lisa Nelson University of Liverpool

The Problem Computers often left on all the time, regardless of whether they are in use Computers often left on all the time, regardless of whether they are in use Changing people’s behaviour is difficult Changing people’s behaviour is difficult Need an automatic power-saving mechanism Need an automatic power-saving mechanism

The Goal Reduce power consumption Reduce power consumption When PCs are idle When PCs are idle Without risking losing data Without risking losing data At no cost At no cost

Use Built-In Windows Capabilities? Hibernate? Hibernate? Excellent power reduction Excellent power reduction Can have issues in network environments Can have issues in network environments Standby? Standby? Good power reduction Good power reduction Same potential issues with network environments Same potential issues with network environments Power down hard disks? Power down hard disks? In practice, did nothing In practice, did nothing Stores settings for the current user! Stores settings for the current user! No management by policy! No management by policy!

Use Third-Party Utilities? Cost Cost Client utilities Client utilities E.g. LocalCooling E.g. LocalCooling All limited to underlying Windows capabilities = same problems All limited to underlying Windows capabilities = same problems Centrally-managed utilities Centrally-managed utilities Can only schedule = less aggressive Can only schedule = less aggressive

Conclusions Shut down Shut down But only when nobody is logged on But only when nobody is logged on Not very aggressive, but safe Not very aggressive, but safe Excellent for walk-up computers Excellent for walk-up computers Can be done with batch files and freeware utilities for £0 Can be done with batch files and freeware utilities for £0

How It Works Setup batch file: Setup batch file: Create a scheduled task to run power-saving batch file (as the System user) after N minutes idle Create a scheduled task to run power-saving batch file (as the System user) after N minutes idle Copy power-saving batch file somewhere local Copy power-saving batch file somewhere local Also copy two freeware utilities Also copy two freeware utilities Power-saving batch file: Power-saving batch file: Determine whether anybody is logged on Determine whether anybody is logged on If not, shut down If not, shut down

Possible Problems Some people may legitimately need to opt out Some people may legitimately need to opt out Running grid applications with nobody logged on Running grid applications with nobody logged on Acting as a server Acting as a server So supply a discretionary opt-out mechanism So supply a discretionary opt-out mechanism Psshutdown flagged as dangerous Psshutdown flagged as dangerous NOT a problem: erroneously shutting down when somebody is logged on NOT a problem: erroneously shutting down when somebody is logged on

Our Results No problems No problems Statistics: Statistics: Shutdowns per day: ~4,500 Shutdowns per day: ~4,500 Total computers participating: ~3,500 Total computers participating: ~3,500 Average daily downtime: 33,350 hours = >1,000,000 hours per month! Average daily downtime: 33,350 hours = >1,000,000 hours per month! Average daily MW (assuming 100 W): 3.3 MW Average daily MW (assuming 100 W): 3.3 MW Average daily kg CO 2 (0.43 kg/kW): 1,400 kg Average daily kg CO 2 (0.43 kg/kW): 1,400 kg

Want to Try It? me: Or go to

Limitations No reporting No reporting Not very flexible Not very flexible Inconvenient to modify after rollout Inconvenient to modify after rollout Not very effective for staff-style working patterns Not very effective for staff-style working patterns

The Big Limitation What if you want to do more?

PowerMan: Overview Single executable Single executable Copy into place and run POWERMAN INSTALL Copy into place and run POWERMAN INSTALL Runs as a service Runs as a service Controlled by group policy Controlled by group policy Easy to modify Easy to modify Built-in reporting Built-in reporting

PowerMan: Features Control monitor, disk, computer idle timeouts Control monitor, disk, computer idle timeouts Actions: log off, stand by, hibernate, power off Actions: log off, stand by, hibernate, power off Specify different actions and timeouts for: Specify different actions and timeouts for: When a user is logged on vs. no user When a user is logged on vs. no user Running on AC vs. DC Running on AC vs. DC Exceptions (files or processes, Server service) Exceptions (files or processes, Server service) Scheduled wake and shutdown Scheduled wake and shutdown

PowerMan: Reporting Built-in reporting Built-in reporting Easily see overviews or detail down to individual computers Easily see overviews or detail down to individual computers Easy to identify your culprits Easy to identify your culprits

How We Use PowerMan Walk-up: Walk-up: Force logoff after 3 hrs idle Force logoff after 3 hrs idle Hibernate after 10 mins when nobody is logged on Hibernate after 10 mins when nobody is logged on Staff: Staff: Can choose what to do when idle: Can choose what to do when idle: When a user is logged on; e.g. stand by after 30 minutes When a user is logged on; e.g. stand by after 30 minutes When nobody is logged on; e.g. hibernate after 10 minutes When nobody is logged on; e.g. hibernate after 10 minutes

Results

Where We Are Now All our power-saving is now being done by PowerMan All our power-saving is now being done by PowerMan Walk-up: <1 hr idle/day Walk-up: <1 hr idle/day Staff: Staff: Still in progress – ~2000 computers yet to choose settings Still in progress – ~2000 computers yet to choose settings But have cut idle time by 25%; anticipate eventually 75% But have cut idle time by 25%; anticipate eventually 75% Previously 1,000,000 hrs/month; anticipate eventually 2,000,000 Previously 1,000,000 hrs/month; anticipate eventually 2,000,000

Want to Try It? Or go to