Re: Leaving the Desktop Market

throttling is disabled now.


-a

On 4 May 2014 21:27, Kevin Oberman <rkoberman_at_gmail.com> wrote:
> On Sun, May 4, 2014 at 10:07 AM, Nathan Whitehorn <nwhitehorn_at_freebsd.org>wrote:
>
>> On 05/04/14 10:05, Allan Jude wrote:
>>
>>> On 2014-05-04 11:47, Allan Jude wrote:
>>>
>>>> On 2014-05-04 10:28, Matthias Apitz wrote:
>>>>
>>>>> El día Saturday, May 03, 2014 a las 04:59:48PM -0700, Kevin Oberman
>>>>> escribió:
>>>>>
>>>>>  On Sat, May 3, 2014 at 1:25 PM, Adrian Chadd <adrian_at_freebsd.org>
>>>>>> wrote:
>>>>>>
>>>>>>  Set it to the lowest available Cx state that you see in dev.cpu.0 .
>>>>>>>
>>>>>>>
>>>>>>>  Available is not required. Set it to C8. That guarantees that you
>>>>>> will use
>>>>>> the lowest available. The correct incantation in rc.conf is "Cmax".
>>>>>> performance_cx_lowest="Cmax"
>>>>>> economy_cx_lowest="Cmax"
>>>>>>
>>>>>> But, unless you want laggy performance, you will probably also want:
>>>>>> hint.p4tcc.0.disabled=1
>>>>>> hint.acpi_throttle.0.disabled=1
>>>>>> in /boot/loader.conf. Low Cx states and TCC/throttling simply don't mix
>>>>>> well and TCC is not effective, as mentioned earlier in this thread.
>>>>>>
>>>>> Re/ powerd I have in /etc/rc.conf:
>>>>>
>>>>> # powerd
>>>>> powerd_enable="YES"
>>>>> powerd_flags="-a max -b adp"
>>>>> #
>>>>> performance_cx_lowest="Cmax"
>>>>> economy_cx_lowest="Cmax"
>>>>>
>>>>> (and the additional hint.* in /boot/loader.conf as well). Which process
>>>>> 'performance_cx_lowest' and 'economy_cx_lowest' target exactly as config
>>>>> values?
>>>>>
>>>>> Thx
>>>>>
>>>>>         matthias
>>>>>
>>>>>  In a pretty unscientific test on my laptop (Lenovo T530 with Intel i5
>>>> 3320M), setting hw.acpi.cpu.cx_lowest=C8 lowered power consumption at
>>>> idle by about 3 watts, which adds about 30-45 minutes to my battery life
>>>> during conservative usage.
>>>>
>>>> Using PCBSD 10, so hint.acpi_throttle.0.disabled=1 was already set
>>>> (apparently solves some issue with powerd on some AMD systems)
>>>>
>>>> I have added hint.p4tcc.0.disabled=1 but not sure where to expect to see
>>>> a difference.
>>>>
>>>>  I see the difference now, with the p4tcc stuff disabled, the lowest
>>> cpufreq is now 1200mhz instead of 150mhz
>>>
>>>
>>>
>> I just set the default for acpi_throttle and p4tcc in HEAD to disabled by
>> adding these line to the default /boot/device.hints. If you want them back,
>> editing your device.hints will restore them. This can be reverted if many
>> people want throttling enabled by default, but all I have heard so far --
>> and for the past many years -- is a unanimous chorus to turn it off.
>> -Nathan
>>
>
> Anyone playing around with Thermal Management should read the article on
> Tom's Hardware on the subject.  It explains things quite nicely. Even I
> could understand it. :-)
> http://www.tomshardware.com/reviews/cpu-cooler-fails,1695-3.html
> The section on Thermal Monitor 2 was new to me as it has been added since I
> last researched this several  years ago. Note the tie-in between TM2 and
> EST rather than simple throttling (skipping N of every 8 clock cycles).
> Section 2 of the article has thermal specs on a lot of processors, too..
>
> Bottom line of the article is to make sure TM2 is enabled and just leave it
> alone to do its thing. No throttling of any sort for power mis-management.
>
> The one area that can stand a close look is the algorithm for adjusting
> EST. It probably will make far less difference than C-states, but it is a
> legitimate power management technique and it is under the control of
> powerd. Several people have suggested modification for this and I think
> it's at least worth a look.
>
> Finally, if we don't default p4tcc and throttling to off and change the
> default for C-states to Cmax, a lot of people will be very unhappy.
> Disabling throttling really must come first.
> --
> R. Kevin Oberman, Network Engineer, Retired
> E-mail: rkoberman_at_gmail.co <rkoberman_at_gmail.com>
> _______________________________________________
> freebsd-current_at_freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-current
> To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org"