[powerstation-owners] PowerStation Fans

[Alexander Graf]

On 26.01.2010, at 02:40, Stefan Nürnberger wrote:

> 
> 
> Am 26.01.10 02:23, schrieb Alexander Graf:
>> 
>> On 26.01.2010, at 02:12, Stefan Nürnberger wrote:
>> 
>>>> Hi All
>>>> 
>>>> I have a PowerStation running YDL 6.2 that overall I must say I am very
>>>> happy with. If I could make it a bit quieter I would be even happier
>>>> still ;-)
>>>> 
>>>> The fan noise is fairly loud on light desktop operation (e.g. browsing,
>>>> emailing etc). Periodically and very suddenly the fans can spin up to
>>>> maximum speed even if the PowerStation is idle and will usually return
>>>> to normal speed within about 30 seconds. Is this type of fan activity
>>>> normal for the PowerStation? - perhaps other users could confirm.
>>>> 
>>> 
>>> Yes that's the normal behavior for the PowerStation.
>>> 
>>>> From reading the mailing list archives I see that the issue of noise
>>>> levels has come up from time to time but there appears to be no
>>>> solution. I was just wondering if anyone has ever found a way of
>>>> controlling the fans?
>>>> 
>>> 
>>> AFAIK the fans are controlled by the BMC. Communication with the BMC should be possible through IPMI. I was able to obtain readings from different temperature sensors this way, but did not find any fan control mechanism. I also think that it would not be very advisable to operate the CPUs at a higher temperature. The better approach would be to utilize the power management features of the processors. Unfortunately there was no cpufreq driver for the 970MP last time I checked. There was only some basic support for the 970FX in the linux kernel. It would be nice if someone could look into that. There is no need for the processors to run at full power when the system is idle. IIRC the 970MP has about 15 different power modes. Switching off unused cores completely would also be nice.
>> 
>> I haven't tried this yet, but while debugging a 970fx target I stumbled across this sysctl setting:
>> 
>> kernel.powersave-nap
>> 
>> which defaults to 0. When set to 1 (enabled), the kernel actually tells the cores to power down. With 0 (disabled) it just loops.
>> 
>> I guess it's worth a try ;-). Please tell me if it helps!
>> 
>> Alex
> 
> You are my personal hero! ;)
> Works like a charm. The system has gone quiet in just a couple of seconds. Thank you so much!

Yeah, same thing happened for my VM - suddenly it went from 100% host CPU usage to 0% ;-). I wonder why that option isn't enabled by default.

Either way, I'm glad I could help.

Alex