Thursday, January 6, 2011

Audio Stuttering in Windows 2008 R2

I’ve been running Windows Server 2008 R2 64bit for my desktop OS at work for a while now.  When playing background music with Windows Media Player, I’ve always had music skipping/stuttering issues.  You can especially notice it when moving windows around or running a high CPU task (like Flash animations).

I think I’ve finally figured out how to fix it.  It looks like in Windows 2008, the audio processes are by default given a CPU priority below low.  Because of that any other program will preempt Windows Media Player which would cause the stuttering.  It turns out that there is a registry key that controls this:

Key: HKLM\Software\Microsoft\Windows NT\CurrentVersion\multimedia\SystemProfile
Value: SystemResponsiveness
Type: REG_DWORD

In Windows 2008 R2, the default value is 100 (decimal).  In Windows Vista this value is 20 (decimal).  The MSDN article describing this registry key says that this value controls “the percentage of CPU resources that should be guaranteed to low-priority tasks. For example, if this value is 20, then 20% of CPU resources are reserved for low-priority tasks.”  It sounds like the remaining percentage is divided up between the open multimedia applications.  I’m going to set this key to 50 (decimal) on my computer and see if that makes a difference.  Rebooting as soon as I can close all of my windows… It looks like that worked.

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1 comment:

  1. Thank you...this fixed my audio stutter on my Server 2008R2 box. Much appreciated!

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