Friday, April 5, 2013

System timer interval 15ms

Windows default system timer interval is 15,6ms


This setting is only possible to change over development.

You can check the current offset using the following commnad:

powercfg /energy


it will create a xml file where you can find:



Platform Timer Resolution:Platform Timer Resolution
The default platform timer resolution is 15.6ms (15625000ns) and should be used whenever the system is idle. If the timer resolution is increased, processor power management technologies may not be effective. The timer resolution may be increased due to multimedia playback or graphical animations.
Current Timer Resolution (100ns units)10000
Maximum Timer Period (100ns units)156001



This means my machine is currently with a timer of 1ms (non default value)


The problem of having this setting is manly the power consumption that consumes more 25%.

In systems running under battery it can be a lot.


You can actually check wich application is requesting that interval, in my case...chrome:



Platform Timer Resolution:Outstanding Timer Request
A program or service has requested a timer resolution smaller than the platform maximum timer resolution.
Requested Period10000
Requesting Process ID2788
Requesting Process Path\Device\HarddiskVolume3\Program Files (x86)\Google\Chrome\Application\chrome.exe



If you need to develop an application with this requirement please check the oficial msft documentation:

http://msdn.microsoft.com/en-us/windows/hardware/gg463266.aspx



As other end if you need to change the timer (debug proposes for example) but don´t have access to the code you can simply install a third party application that actually does that.... for examle chrome (when running flash) or x-lite (voip phone)...








Other links regarding clock performance and other settings related with bcdedit and HPET:


Alguns links



Maquina IBM com problemas de performance que recomendam activar o settings:



Detalhes do comando:




Outros







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