Multimedia Class Scheduler - W7

Clanger

Well-Known Member
Stopping the Multimedia Class Scheduler service stops Windows Audio service. Can they be split so Multimedia Class Scheduler can be removed or can its settings be changed?

Ive found some settings at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia. I have found some settings named Scheduling Category. Pro Audio is High, others are Medium. I wonder if this would help with denywinarto and his gaming lag issues.

ASIO4ALL can handle audio but not audio and video so i wonder if the settings above will help with the audio and video synce issue with vlc and w10 1607.

These are the Pro Audio settings, apply them to to the Audio, Games and Playback settings. Professional Audio is a high priority thing then apply the same settings to the other tasks may help with audio video and gaming performance.

I havnt found detailed information on all of the settings and their value so i would need todo some hunting.

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile\Tasks\Pro Audio]
"Affinity"=dword:00000000
"Background Only"="False"
"Clock Rate"=dword:00002710
"GPU Priority"=dword:00000008
"Priority"=dword:00000001
"Scheduling Category"="High"
"SFIO Priority"="Normal"

Or we can split the Windows Audio and Multimedia Class Scheduler services.
Open RegEdit and go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Audiosrv. Export this branch as a backup.
Modify DependOnService on the right hand pane.
Remove MMCSS. Exit RegEdit

Open Control Panel\All Control Panel Items\Administrative Tools\Services. Double click Multimedia Class Scheduler service. Set Startup type to Disabled. Stop the service, Click Apply and OK. Reboot.

Whether this has any affect or not is open to discussion, some say its snake oil. I dont game so i dont know if it helps gaming or not. Best bet is to split the services 1st, see if that affects frame rates and lagging. If not try changing the values at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile\Tasks.
Decide for yourself if these tweaks work or not.
 
Last edited:

AeonX

Active Member
I preferred to leave this service activated because I don't know the consequences.

Some say that in Windows 10 this causes an increase in DPC latency. I don't know how to test this.

From the description of the service it seems that disabling it will cause these settings to be ignored.
 

Clanger

Well-Known Member
windows assumes you are running a full bore system and multitasking blah blah blah. when i run an audio or video program, that is all i am doing, running 1 program so i dont have to worry about av getting its fair share of resources
 
Last edited:
Top