sony-vaio-z-series team mailing list archive

[Rutger Hendriks <rutgerhendriks@xxxxxxxxx>]

Hmm, powertop tells me the system uses around 20 W. That's with the default
Ubuntu 10.10 AMD64. Any quick gains to be had?

Op 6 okt 2010 12:15 schreef "Adam Hill" <sidepipeuk@xxxxxxxxx>:

Hi Knuth,


> You mentioned that you integrated the NOHZ patch.
       Actually I didn't, all I did was enable CONFIG_NO_HZ. The patch that
Norbert posted is already in the 2.6.35-rc6 base kernel that I used.


> Did it influence your power consumption?
       Creating a tickless kernel made a bit of difference, yes.


> And did you have accessive occurrences of
> 34.2% (185.3) [kernel scheduler] Load balancing t...
       I have ( currently )

Cn                Avg residency       P-states (frequencies)
C0 (cpu running)        ( 0.4%)       Turbo Mode     9.5%
polling           0.3ms ( 0.0%)         2.67 Ghz     0.0%
C1 mwait          0.2ms ( 0.1%)         2.54 Ghz     0.0%
C2 mwait          0.8ms ( 0.0%)         2.40 Ghz     0.0%
C3 mwait         35.6ms (99.5%)         1199 Mhz    90.5%

Wakeups-from-idle per second : 33.6     interval: 20.0s
Power usage (ACPI estimate): 10.6W (5.4 hours)

Top causes for wakeups:
 54.3% ( 45.0)   [kernel scheduler] Load balancing tick
 11.5% (  9.5)   [kernel core] hrtimer_start (tick_sched_timer)
  9.1% (  7.5)   [ahci] <interrupt>
  6.7% (  5.5)   events/3

       I don't think that 10.6W is a bad result for a core i7 system :). In
reality though power use is normally a bit higher if I actually DO anything!


> Also: Norbert mentioned to send the HDD to sleep. Does this make sense
> with SSD drives?
       Good question, and one to which I don't really know the answer. You
would
imagine that an SSD uses very little power when it isn't being accessed
anyway, so any gains that there may be would probably not make up for the
reduced performance of having to wake it up again.

Adam.



> Thanks!
>
> Knuth
>
> ---
>
> On 10/05/2010 11:16 AM, Adam Hill wrote:
> >> @Adam: I'll so lo...