frequency scaling on D525MW not working properly

william opensource4you william.os4y at
Wed Jul 25 01:05:54 PDT 2012


just my 2 cents :-)

since one week, I'm just installing dbsd on an hp-mini: Atom N455.

I've no CPU related issues.

here sysctl out put:
hw.acpi.cpu.cx_lowest: C1
hw.acpi.cpu.px_dom0.available: 1666 1333 1000
hw.acpi.cpu.px_dom0.members: cpu0(1000) 1000
hw.acpi.cpu.px_global: 1666
hw.acpi.cpu0.cx_supported: C1/1 C2/1 C3/57
hw.acpi.cpu0.cx_lowest: C1
hw.acpi.cpu0.cx_usage: 100.00% 0.00% 0.00% last 5000us
hw.acpi.cpu1.cx_supported: C1/1 C2/1 C3/57
hw.acpi.cpu1.cx_lowest: C1
hw.acpi.cpu1.cx_usage: 100.00% 0.00% 0.00% last 5000u

powerd sounds to work:

dfly# powerd -d
qavg= 0.02 savg= 0.00  1/ 1 ncpus=0
dom0 set frequency 1000
qavg= 1.02 savg= 0.34  0/ 0 ncpus=1
dom0 set frequency 1666
qavg= 0.00 savg= 0.22  1/ 1 ncpus=0
dom0 set frequency 1000
qavg= 0.49 savg= 0.28  0/ 0 ncpus=1

Please note that I'm using dbsd current (21/07/2012).

if I can help to perform additional tests ... do not hesitate, this is
test machine.



Later I will post more details about what is working and what not.

On Mon, Jul 23, 2012 at 9:54 PM, Sven Gaerner <sgaerner at> wrote:
> On Mon, Jul 23, 2012 at 10:28:14AM +0000, Adrian Bocaniciu wrote:
>> Intel Atom processors, unlike more expensive Intel processors, do not
>> support frequency scaling.
>> See for example the specifications for Atom D525 at:
>> where it is stated that Enhanced Intel SpeedStep Technology is not
>> supported. The same is written in all Atom datasheets.
>> The only way to reduce the power consumption of Atom is to ensure that
>> the processor is halted when it has nothing to do, i.e. in the idle
>> loop, which I suppose that DragonFlyBSD does, or to use the ACPI C3
>> sleep state whenever you can tolerate the latency required for waking up
>> the processor.
>> I also have a couple of D525MW boards, but I have not tested
>> DragonFlyBSD on them, and they are much less warm, but my Mini-ITX cases
>> (Lian Li & Antec) have case coolers that ensure an adequate air flow
>> inside the cases even if both the motherboards and the power supplies
>> are fanless.
> Thanks for the details. I did not look at that point as I expected at
> least frequency scaling which is supported by the Atom on the Fit-PC2 I
> also use.
> I think I will try to get the temperature down by using a fan. But then
> it is no longer a fanless system that I wanted to have running all the
> time. And a system in a mini-ITX case with a temperature of 55 degrees
> is not what I want to have running all the time.
> Thanks all for the help. I guess I will have to think about a
> replacement to get a cooler fanless system.
> Regards,
> Sven

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