[ltp] Re: Re: Stress testing for undervolting

[Identity Guarded]

Laurent Gilson wrote:

> First i searched the absolute minimum voltage for each frequency by
> running mprime and decreasing the voltage by 1 step every 10 seconds. That
> way i found the drop-off points (and crashed/rebooted 2-3 times).
> Afterwards i increased every voltage by 1 step (2 for the ones that
> crashed hard).

Yeah... that's about as far as I've gotten (the easy part).
=20
> Then 2 hours torture test with all the things i wrote in the first mail
> (mprime, seeks, WLAN, changing the frequency via script every 30 sec). No
> crashs, no error in mprime. But it still didn=B4t "feel" safe so i added
> another step to each voltage.

Do you still have this script?  It might be interesting to see it explicitl=
y. =20
In your first post you mentioned that you unplugged/replugged the AC and th=
e=20
battery.  Did you do that physically/manually?  Or could you do it "soft" v=
ia=20
a script?

>=20
> After 3 hours surfing/office my CPU is at 42-45=B0C, w/o any fan running.=
 I
> have 3:45 runtime from a 40Wh battery (with WLAN switched on but bluetooth
> off) (IBM promises 3:00 for a 47Wh... go figure). I didn=B4t bother to ch=
eck
> if the last "safety" step was really necessary.

That's nice.  I'm curious.  It sounds as though you're about as careful wit=
h=20
under-volting as I would like to be.  Did you try to dig a little more powe=
r=20
conservation by messing with the fan speeds/triggers?  I'm really=20
apprehensive to go so far.  It seems to me that if temperatures are really=
=20
lower, then fan usage should drop without any further tinkering.  For now,=
=20
I'm just leaving the fan as is.

=2DSukant