[arch-general] powertop vs archlinux vs ubuntu

[Stefano Z.]

hi

i've bought a new notebook (hp pavilion dm1-1150sl) and installed
archlinux.
i have see a strange thing with powertop, i'm running the vanilla arch kernel26,
and i have see this behaviour:
Cn                Avg residency       P-states (frequencies)
C0 (cpu occupata)      (31,6%)
C0                0,0ms ( 0,0%)
C1 mwait          0,1ms ( 0,7%)
C4 mwait          0,0ms (67,8%)
Wakeups-from-idle per second : 31483,5  interval: 10,0s
---
as you can see, i have a LOT of wakeups per seconds very low c1 states
lot of c0 and c4 states,
a wattmeter tell me that archlinux consume about 25/26watt
Then i have boot a live ubuntu distro and see this:
Cn                permanenza media    P-state (frequenze)
C0 (cpu occupata)      ( 0,6%)
polling           0,0 ms ( 0,0%)
C1 mwait         26,7 ms (68,6%)
C4 mwait          1,2 ms (30,8%)
Wakeup-da-idle al secondo: 281,3        intervallo: 15,0s
---
as you can see  the wakeups are a LOT lower than on arch and we have
lot of c1 and c4 state,
power consumption is about 20W, the same that i have with win7 (about 18/20w).
For meaning about cX state see here:
http://www.lesswatts.org/projects/powertop/powertop.php

thanks!