Re: SheevaPlug power usage
On Tue, 2009-03-17 at 11:17 +0100, Laurent GUERBY wrote:
> On Mon, 2009-03-16 at 20:42 +0100, Martin Michlmayr wrote:
> > * Rainer Dorsch <firstname.lastname@example.org> [2009-03-16 20:00]:
> > > just seen your SheevaPlug blog entry
> > > http://www.cyrius.com/journal/debian/kirkwood/sheevaplug/nslu2-killer
> > >
> > > Do you have meassured power consumption numbers for the SheevaPlug vs nslu2?
> > No, unfortunately I don't have the equipment to measure power
> > consumption.
> Here is what I measured with an Energy Monitor 3000, SheevaPlug on 220V:
> 3.1W just on, Linux booted
> 3.3W serial
> 4.3W serial + ethernet
> 6.0W serial + ethernet + USB HDD
> 7.0W serial + ethernet + USB HDD + 100% cpu
> cos phi moves from 0.46 to 0.51. USB HDD is Lacie Porshe 120GB IDE with
> disk "SAMSUNG HM120JC version YL10", I use it for swap, root is on NFS.
Thanks to two new patches queued for git://git.marvell.com/orion.git
idle consumption is significantly improved in my setup:
2.3W Idle with everything unpluged
3.3W Idle with gigabit ethernet
5.0W Idle with gigabit+HDD USB+serial
7.0W +100% cpu
cos phi is in the 0.5 range.
When cpu is loaded but not completely the power usage should also
be lower but it's harder to measure in my setup.
powertop 1.11 report on a mostly idle system:
Cn Avg residency
C0 (cpu running) ( 0.0%)
C0 9.8ms ( 0.5%)
C1 402.7ms (99.6%)
Kernel config options to enable:
Also on the performance front: a native kernel compile from scratch with
"Gentoo 4.1.2 p1.3" GCC takes around 50 minutes.