WinXP laptop dynamic speed power management problem

External Since: Dec 17, 2005 Posts: 307

Been using a Gateway laptop with a single-core Turion for a while now. I
used to keep its power management setting on either "Portable/Laptop" or
on "Minimal Power Management" most of the time. Using a utility called
MobileMeter, I used to notice its speed reduce from full (1.8Ghz) to a
slow power-saving frequency (800Mhz), due to the AMD PowerNow power
management feature (it's the equivalent of SpeedStep on Intel
processors). That was all fine and good, that's what I wanted. But
recently I started noticing that it lasts a lot less time while under
battery power. So I watched it under MobileMeter again, and noticed that
now the laptop stays 100% of the time on its full speed rather than
going into power saving speed, even if there is not too much activity on
the system.

So then I switched from the "Portable/Laptop" or the "Minimal Power
Management" schemes to the "Max Battery" scheme. And now battery life is
back to normal. But I wonder what could've happened to make the two
previous suitable schemes become unsuitable? I can't think of any major
changes on the laptop, and the CPU loads seem to be idle most of the
time, just as it always used to be. I consider this to be a workaround
rather than a fix.

How does Windows figure out when to switch to lower speed mode, and what
could've changed to interfere with it?

Yousuf Khan

External Since: Oct 09, 2004 Posts: 2479

Yousuf Khan wrote:
> Been using a Gateway laptop with a single-core Turion for a while now. I
> used to keep its power management setting on either "Portable/Laptop" or
> on "Minimal Power Management" most of the time. Using a utility called
> MobileMeter, I used to notice its speed reduce from full (1.8Ghz) to a
> slow power-saving frequency (800Mhz), due to the AMD PowerNow power
> management feature (it's the equivalent of SpeedStep on Intel
> processors). That was all fine and good, that's what I wanted. But
> recently I started noticing that it lasts a lot less time while under
> battery power. So I watched it under MobileMeter again, and noticed that
> now the laptop stays 100% of the time on its full speed rather than
> going into power saving speed, even if there is not too much activity on
> the system.
>
> So then I switched from the "Portable/Laptop" or the "Minimal Power
> Management" schemes to the "Max Battery" scheme. And now battery life is
> back to normal. But I wonder what could've happened to make the two
> previous suitable schemes become unsuitable? I can't think of any major
> changes on the laptop, and the CPU loads seem to be idle most of the
> time, just as it always used to be. I consider this to be a workaround
> rather than a fix.
>
> How does Windows figure out when to switch to lower speed mode, and what
> could've changed to interfere with it?
>
> Yousuf Khan

This is just a guess, but could it be related to this ? I know you
have a single core processor, but maybe this change affects power
management.

http://support.microsoft.com/kb/896256

Paul