dwm.exe process priority. How it's priority affects system performance/stability

from Stardock Forums

I'm using Windows Blinds 6.4 under Vista32; and no plans to upgrade Windows Blinds or Windows OS version.  I noticed that the only Windows Blinds processes I can identify... WBVista.exe and VistaSrv.exe are both set to Realtime.  I know its general rule of thumb in most cases to never to set a process at Realtime. 

Having said the above; what kind of an impact would it have on Windows OS if I change the process priority of dwm.exe to Realtime (from the default "High" setting)?  What kind of an impact would it have on the OS if I set it to "Low"?  I'm using transparency with a Windows Aero-like theme.

I use EVR and other directshow/direct3D related tasks to watch Bluray movies (scaled to a window and/or full resolution/full screen) most of the time (with Aero glass in full effect.  Of course, I dont want to introduce instability to a rock solid setup; however, if I can increase performance in one area (even a little bit), without it affecting stability or adversely degrading performance in another Windows component I need, I wouldn't mind.  If it ends up reducing performance for something I dont use that much, I wouldnt mind either. 

I would prefer someone to answer that knows the answer for sure on this; instead of guessing different possibilities like I am now.  I did try the "realtime" setting, but was too nervous to leave dwm.exe at that for too long.  I also tried "Low", but wasn't sure what to expect.  Both didn't cause any immediate instability no my display.

windowblinds
15,305 views 6 replies
Reply #1 from WinCustomize Forums Top

well I don't know for sure

 

but I would say try it out for a day or two and see what happens ... I would say the worst that could happen is your PC may freeze  and if so just set it back...

 

note I don't know .... part of leaning something is to just do it...

Reply #2 from WinCustomize Forums Top

Quoting DisturbedComputer, reply 1
note I don't know .... part of leaning something is to just do it...
End of DisturbedComputer's quote

DC ... I think mkanet is looking for a definitive answer so as to avoid 'dramas' ...;)

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Reply #3 from WinCustomize Forums Top

Leave it be.  DWM is a Direct-3D application that controls the display and update of windows on the desktop by aggregating screen content through WDDM. It must be set to high.

I dont want to introduce instability to a rock solid setup
End of quote

Then don't.

Reply #4 from WinCustomize Forums Top

Ah ...a definitive answer...;)

Reply #5 from Stardock Forums Top

Thanks, I already know its stable when set to high.  I'm more interested in knowing what happens if I increase DWM process priority to realtime, that would make OS window drawing quicker, without introducing instability?  Would that possibly degrade performance for other direct3D rendering done at the same time?  Almost everything I do on my desktop is directshow/EVR (MediaCenter type stuff).  I'm curious how it would affect that when set to realtime.

Quoting yrag, reply 3
Leave it be.  DWM is a Direct-3D application that controls the display and update of windows on the desktop by aggregating screen content through WDDM. It must be set to high.


I dont want to introduce instability to a rock solid setup

Then don't.
End of yrag's quote

Reply #6 from WinCustomize Forums Top

You're skirting precariously close to the clinical definition of insanity.

I don't know how many different ways I can say this.....

A realtime priority thread can never be pre-empted by timer interrupts and runs at a higher priority than any other thread in the system. As such, a CPU bound realtime priority thread can totally hose a machine.


If that's your goal, knock yourself out.