Logos 5 modifies Window's Platform Timer Resolution
In Windows 7 and 8 it is posible to run from the Command Prompt (admin) the command powercfg -energy, which will generate a report on the use of energy by the computer and identify possible problems.
If one does so with Logos 5 open, the report informs you that Logos 5 has asked Windows to lower it Platform Timer Resolution from 15ms down to 1ms. Apparently this is helpful with certain video tasks, but also reduces battery life by about 10% (cf. http://software.intel.com/en-us/articles/power-analysis-guide-for-windows#_Toc343774425 and http://blogs.msdn.com/b/e7/archive/2009/01/06/windows-7-energy-efficiency.aspx).
I was wondering what the motivation behind this is (performance?), and whether Logos could at least set the Platform Timer Resolution back to 15ms while idle? Here I am thinking about battery life more than anything else.
Comments
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This is caused by WPF (http://randomascii.wordpress.com/2013/07/08/windows-timer-resolution-megawatts-wasted/, http://social.msdn.microsoft.com/Forums/vstudio/en-US/d39edd26-5db3-4803-a536-6d39bb16c50c/on-app-launch-wpfgfxv0300dll-is-calling-timebeginperiod1); it's not something we can easily avoid, unfortunately.
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So what you're saying is that Logos uses WPF, WPF sets the timer to a higher frequency, and then reports the requesting software as Logos?
Russ
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Thanks, Bradley.
Russ White said:So what you're saying is that Logos uses WPF, WPF sets the timer to a higher frequency, and then reports the requesting software as Logos?
Russ
In the energy report created by Windows, it says:
Platform Timer Resolution:Timer Request StackThe stack of modules responsible for the lowest platform timer setting in this process.Requested Period 10000 Requesting Process ID 3916 Requesting Process Path \Device\HarddiskVolume2\Users\droza\AppData\Local\Verbum\System\Verbum.exe Calling Module Stack \Device\HarddiskVolume2\Windows\SysWOW64\ntdll.dll \Device\HarddiskVolume2\Windows\SysWOW64\kernel32.dll \Device\HarddiskVolume2\Windows\Microsoft.NET\Framework\v4.0.30319\WPF\wpfgfx_v0400.dll \Device\HarddiskVolume2\Windows\SysWOW64\kernel32.dll \Device\HarddiskVolume2\Windows\SysWOW64\ntdll.dll Logos, it would seem, is calling wpfgfx_v0400.dll. The 2nd article Bradley cited is a forum complaint that wpfgfx_v0300.dll lowers the Timer Resolution from 15 to 1ms. My guess is that Logos would have to stop calling wpfgfx_v0400.dll in order to avoid changing the Timer frequency.
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Russ White said:
then reports the requesting software as Logos?
The process (Logos) is "responsible" for the actions of all DLLs it loads (WPF).
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Any program using WPF may report this. I see others on my computer reporting the same thing, including the browser Chrome.
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