[LAU] Balance between performance and noise

[rosea.grammostola]

On 11/27/2010 01:15 PM, Leigh Dyer wrote:
> On Sat, 2010-11-27 at 11:24 +0100, rosea.grammostola wrote:
>    
>> Hi,
>>
>> When I set cpu scaling with sudo cpufreq-set -g performance, I have the
>> best proaudio performance on my thinkpad T61. But, that will also heat
>> things up very quickly with as consequence more sound from the fans.
>>
>> The laptop is more silent when I use, sudo cpufreq-set -g ondemand, but
>> I get more xruns then.
>>
>> Is it possible to adjust the ondemand settings to find more balance
>> between performance and noise? How?
>>      
> You'll almost certainly be getting xruns not because the CPU is running
> slower sometimes in "ondemand" mode, but because the CPU is changing
> between fast and slow speeds. This speed change causes the CPU to pause
> momentarily, and can very easily cause xruns; I've found that this is a
> really common cause of JACK xrun issues with laptops.
>
> The good thing is that, unless you're doing something quite CPU
> intensive, you might be able to run your CPU at its lowest speed -- as
> long as it's not changing speeds, you still shouldn't see xruns. Setting
> the CPU governor to "conservative" will lock you in at your CPU's lowest
> speed.
>
> If that's not enough, you might be able to set your CPU to a specific
> speed that's still lower than its maximum -- I know my 2.4Ghz laptop has
> both 800Mhz and 1.6Ghz settings, for instance.
>
> Thanks
> Leigh
>    
>>
>> Btw., I use thinkfan to control the temperature and fan speed
>> http://thinkfan.sourceforge.net/
>>
>> My /etc/thinkfan.conf settings are:
>>
>> sensor /proc/acpi/ibm/thermal (2, 7, 8, 0, 0, 0, 7, 0, 12, 5, 5)
>>
>>
>>    (0,    0,    54)
>>    (1,    50,    57)
>>    (2,    52,    59)
>>    (3,    54,    63)
>>    (4,    56,    65)
>>    (5,    59,    66)
>>    (7,    63,    32767)
>>      

Has a choice between Jack1 and Jack2 any influence on 'the balance 
between performance and noise' (on a dualcore)? Does one or the other 
have higher cpu load etc. ?

Regards,

\r