A simple test to determine effect of SATA link power management settings on power consumption.
Runlevel: singleuser (X11)
ETA: 10 minutes
How to test
- Make sure laptop battery is fully charged.
- Reboot laptop to single user mode.
- Unplug AC power from the laptop.
for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo max_performance > $i; done
powertop -d -t 60 | grep 'Power usage'
- Record the power usage estimate printed in Watts. This will be the power consumption at the max_performance setting.
for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo medium_power > $i; done
powertop -d -t 60
Please add the following to the results table.
- Power consumption for all three link power settings, max_performance, medium_power, min_power.
- Your smolt system profile. (no need to resubmit if you have already for one of the other tests)
- Please open bugs if you notice any abnormal behavior such as system hangs, kernel oops messages, serious IO performance degradation.
- You may return your system to its default state by running the command in step 4 again or just reboot.