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Revision as of 19:04, 21 October 2009 by Jlaska (talk | contribs) (Use the {{!}} template to mimic a PIPE)


A simple test to determine effect of SATA link power management settings on power consumption. Privileges: Root
Runlevel: singleuser (X11)
ETA: 10 minutes

How to test

  1. Make sure laptop battery is fully charged.
  2. Reboot laptop to single user mode.
  3. Unplug AC power from the laptop.
  4. run: for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo max_performance > $i; done
  5. run: powertop -d -t 60 | grep 'Power usage'
  6. Record the power usage estimate printed in Watts. This will be the power consumption at the max_performance setting.
  7. run: for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo medium_power > $i; done
  8. run: powertop -d -t 60

Expected Results

Please add the following to the results table.

  1. Power consumption for all three link power settings, max_performance, medium_power, min_power.
  2. Your smolt system profile. (no need to resubmit if you have already for one of the other tests)
  3. Please open bugs if you notice any abnormal behavior such as system hangs, kernel oops messages, serious IO performance degradation.
  4. You may return your system to its default state by running the command in step 4 again or just reboot.