Windows 10: Change Split Threshold for svchost.exe in Windows 10

How to: Change Split Threshold for svchost.exe in Windows 10

How to Change Split Threshold for svchost.exe in Windows 10


Information Starting with RAM.

If your PC has 3.5+ GB of memory, you may notice an increased number of processes in Task Manager. While this change may look concerning at first glance, many will be excited to find out the motivation behind this change. As the number of preinstalled services grew, they began to get grouped into processes known as service hosts (svchost.exe’s) with Windows 2000. Note that the recommended RAM for PC’s for this release was 256 MB, while the minimum RAM was 64MB. Because of the dramatic increase in available memory over the years, the memory-saving advantage of service hosts has diminished. Accordingly, ungrouping services on memory-rich (3.5+ GB of RAM) PCs running Windows now offers us the opportunity to do the following:
1. Increase reliability: When one service in a service host fails, all services in the service host fail. In other words, the service host process is terminated resulting in termination of all running services within that process. Individual service failure actions are then run. As you may have noticed in Task Manager before, service hosts can contain a lot of services:




2. Increase transparency: Task Manager will now give you a better view into what is going on behind the scenes. You can now see how much CPU, Memory, Disk & Network individual services are consuming.

To see the name of the service, click on the left-most arrow such that the Display name drops down. Alternatively, right-click on the header and select ‘Command Line’ to add the Command Line column. Service names will be listed in the format ‘svchost.exe -k <svchost name> -s <service name>.’







3. Reduce servicing costs: Following reports of instability, service engineers, IT admins, and Microsoft engineers can rapidly pinpoint issues to the exact service and fix it.

4. Increase security: Process isolation and individual permission sets for services will increase security.
Note that critical system services (services whose recovery require system restarts), as well as a couple of select service hosts, will remain grouped.

If your PC has less than 3.5 GB of RAM, the classic service management model will be used. Services will be grouped like in previous versions of Windows.


If wanted, you can configure how Windows 10 splits up svchost.exe processes by changing the value of the SvcHostSplitThresholdInKB DWORD. This DWORD can be used to reduce the amount of svcshost.exe processes by increasing the threshold for when the service processes split.

The default and recommended behavior is having more svcshost.exe processes for the reasons above by leaving the SvcHostSplitThresholdInKB DWORD set to 380000.

This tutorial will show you how to change the split threshold for svchost.exe processes for all users in Windows 10.

You must be signed in as an administrator to change the SvcHostSplitThresholdInKB value.


Here's How:

1. Press the Win+R keys to open Run, type regedit into Run, and click/tap on OK to open Registry Editor.

2. Navigate to the key below in the left pane of Registry Editor. (see screenshot below)
*Arrow HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control




3. In the right pane of the Control key, double click/tap on the SvcHostSplitThresholdInKB DWORD to modify it. (see screenshot above)

4. Type the value from the table below based on the amount of RAM (memory) in KB your PC has or if you want to restore this back to default, and click/tap on OK. (see screenshot below)


Note Example formula for value:

8 GB = 8x1024 MB = 8x1024x1024 KB = 8388608 KB

[table][tr][td]RAM[/td] [td]Value[/td] [/tr] [tr][td](default)[/td] [td]380000[/td] [/tr] [tr][td]4 GB[/td] [td]4194304[/td] [/tr] [tr][td]6 GB[/td] [td]6291456[/td] [/tr] [tr][td]8 GB[/td] [td]8388608[/td] [/tr] [tr][td]12 GB[/td] [td]12582912[/td] [/tr] [tr][td]16 GB[/td] [td]16777216[/td] [/tr] [tr][td]24 GB[/td] [td]25165824[/td] [/tr] [tr][td]32 GB[/td] [td]33554432[/td] [/tr] [tr][td]64 GB[/td] [td]67108864[/td] [/tr] [/table]



5. Close Registry Editor.

6. Restart the computer to apply.


That's it,
Shawn


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Multiple instances are running for Svchost.exe in Windows 10 task manager

I have been having %100 disk activity that nearly freezes the machine for minutes+ for some time now (several months) and after looking over tasks running with procexp.exe I discovered multiple instances of svchost.exe that have identical command lines.
I'm convinced that this is a problem if not the problem. Any ideas how to fix this?

Microsoft Windows [Version 10.0.15063]

Here are command lines for all 82 instances at the moment:

C:\WlNDOWS\System32\svchost.exe -k utcsvc

c:\windows\system32\svchost.exe -k unistacksvcgroup -s an UserService

c:\windows\system32\svchost.exe -k unistacksvcgroup -s CDPUserSvc

o:\windows\system32\svchost.exe -k unistacksvcgroup

C:\WlNDOWS\system32\svchost.exe -k RFCSS

C:\WlNDOWS\system32\svchost.exe -k NetwocherviceNetworkRestricted

C:\WINDOWS\System32\svchost.exe -k NetworkService

C:\WINDOWS\System32\svchost.exe -k NetworkService

C:\WINDOWS\System32\svchost.exe -k NetworkService

C:\WlNDOWS\system32\svchost.exe -k NetworkService

C:\WlNDOWS\system32\svchost.exe -k NetworkService

C:\WlNDOWS\system32\svchost.exe -k NetworkService

C:\WlNDOWS\system32\svchost.exe -k netsvcs

C:\WlNDOWS\system32\svchost.exe -k netsvcs

C:\WlNDOWS\system32\svchost.exe -k netsvcs

C:\WlNDOWS\System32\svchost.exe -k netsvcs

C:\WINDOWS\system32\svchost.exe -k netsvcs

C:\WINDOWS\system32\svchost.exe -k netsvcs

C:\WINDOWS\System32\svchost.exe -k netsvcs

C:\WINDOWS\System32\svchost.exe -k netsvcs

C:\WINDOWS\system32\svchost.exe -k netsvcs

C:\WINDOWS\systern32\svchost.exe -k netsvcs

C:\WINDOWS\System32\svchost.exe -k NetSvcs

C:\WINDOWS\systern32\svchost.exe -k netsvcs

C:\WINDOWS\Systern32\svchost.exe -k netsvcs

C:\WINDOWS\Systern32\svchost.exe -k netsvcs

C:\WlNDOWS\systern32\svchost.exe -k netsvcs

C:\WlNDOWS\system32\svchost.exe -k netsvcs

C:\WlNDOWS\system32\svchost.exe -k netsvcs

C:\WlNDOWS\system32\svchost.exe -k netsvcs

C:\WINDOWS\system32\svchost.exe -k netsvcs

C:\WINDOWS\system32\svchost.exe -k netsvcs

C:\WINDOWS\system32\svchost.exe -k LocalSystem NetworkRestricted

C:\WINDOWS\System32\svchost.exe -k LocalSystem NetworkRestricted

C:\WlNDOWS\system32\svchost.exe -k LocalSystem NetworkRestricted

C:\WlNDOWS\system32\svchost.exe -k LocalSystem NetworkRestricted

C:\WINDOWS\System32\svchost.exe -k LocalSystem NetworkRestn'cted

C:\WlNDOWS\system32\svchost.exe -k LocalSystem NetworkRestn'cted

C:\WlNDOWS\system32\svchost.exe -k LocalSystem NetworkRestn'cted

C:\WlNDOWS\system32\svchost.exe -k LocalSystem NetworkRestricted

C:\WlNDOWS\system32\svchost.exe -k LocalSystem NetworkRestricted

C:\WINDOWS\System32\svchost.exe -k LocalSystem NetworkRestricted

C:\WINDOWS\System32\svchost.exe -k LocalSystem NetworkRestn'cted

C:\WINDOWS\System32\svchost.exe -k LocalSystem NetworkRestn'cted

C:\WlNDOWS\system32\svchost.exe -k LocalServiceNo Network

C:\WINDOWS\System32\svchost.exe -k LocalServiceNo Network

C:\WINDOWS\System32\svchost.exe -k LocalServiceNo Network

C:\WlNDOWS\system32\svchost.exe -k LocalServiceNetworkRestricted

C:\WINDOWS\System32\svchost.exe -k LocalServiceNetworkRestricted

C:\W|NDOWS\system32\svchost.exe -k LocalServiceNetworkRestricted

C:\WINDOWS\System32\svchost.exe -k LocalServiceNetworkRestricted

C:\WINDOWS\System32\svchost.exe -k LocalServiceNetworkRestricted

C:\WlNDOWS\system32\svchost.exe -k LocalServiceNetwodtRestricted

C:\WINDOWS\System32\svchost.exe -k LocalServiceNetwodtRestricted

C:\WlNDOWS\system32\svchost.exe ~k LocalServiceNetwodtRestricted

C:\WINDOWS\System32\svchost.exe ~k LocalServiceNetwodtRestricted

C:\WINDOWS\System32\svchost.exe ~k LocalServiceNetworkRestricted

C:\WlNDOWS\system32\svchost.exe ~k LocalServiceAndNolmpersonation

C:\WlNDOWS\system32\svchost.exe ~k LocalServiceAndNolmpersonation

C:\WlNDOWS\system32\svchost.exe ~k LocalServiceAndNolmpersonation

C:\WlNDOWS\system32\svchost.exe -k LocalServiceAndNolmpersonation

C:\W|NDOWS\System32\svchost.exe -k LocalServiceAndNolmpersonation

C:\W|NDOWS\system32\svchost.exe -k LocalService

C:\W|NDOWS\system32\svchost.exe -k LocalService

C:\W|NDOWS\System32\svchost.exe -k LocalService

C:\W|NDOWS\system32\svchost.exe -k LocalService

C:\W|NDOWS\system32\svchost.exe -k LocalService

C:\W|NDOWS\system32\svchost.exe -k LocalService

C:\W|NDOWS\System32\svchost.exe -k LocalService

C:\W|NDOWS\system32\svchost.exe -k LocalService

C:\W|NDOWS\system32\svchost.exe -k LocalService

C:\WlNDOWS\System32\svchost.exe -k LocalService

C:\WINDOWS\system32\svchost.exe -k LocalService

C:\WlNDOWS\system32\svchost.exe -k imgsvc

C:\WINDOWS\system32\svchost.exe -k iissvcs

C:\WlNDOWS\system32\svchost.exe -k ftpsvc

c:\windows\system32\svchost.exe -k devicesflow -s DevicesFlow UserSvc

C:\WINDOWS\system32\svchost.exe -k DcomLaunch

C:\WINDOWS\system32\svchost.exe -k DcomLaunch

C:\WINDOWS\system32\svchost.exe -k DcomLaunch

C:\WINDOWS\system32\svchost.exe -k appmodel

C:\WINDOWS\system32\svchost.exe -k appmodel

 

Win10 1703 runs lots of svchost.exe processes

This changed in Windows 10 version 1703

Service hosts are split into separate processes on PCs with 3.5 GB+ of RAM:
If your PC has 3.5+ GB of memory, you may notice an increased number of processes in Task Manager. While this change may look concerning at first glance, many will be excited to find out the motivation behind this change. As the number of preinstalled
services grew, they began to get grouped into processes known as service hosts (svchost.exe’s) with Windows 2000. Note that the recommended RAM for PC’s for this release was 256 MB, while the minimum RAM was 64MB. Because of the dramatic increase in available
memory over the years, the memory-saving advantage of service hosts has diminished

Taken from

Announcing Windows 10 Insider Preview Build 14942 for PC - Windows Experience Blog

 

really nice post... thanks for the valuable information *Smile

 

Shawn, I have 32GB mem, mine is currently set to 380000 (default) in registry and there are no grouped services showing in task manager. Total processes vary from 195-220. I'm not clear on what affect changing the Reg to the 32GB value of 33554432 would do. I have not tried it yet.

 

You can disable splitting svchost per a service in case of problems, like when Xbox's sign-in fails: Code: reg add "HKLM\System\CurrentControlSet\Services\XblAuthManager" /v "SvcHostSplitDisable" /t REG_DWORD /d "1" /f[/quote]

 

I have been using it for quite some time, it reduces my processes from 120 to around 70 + when Idle. See the image below but that is with Firefox running.

 

Thanks, Josey. But I thought the whole purpose was to create more, smaller SVCHOST processes, to isolate and manage and protect from 1 service taking down 20 or more. Maybe I just don't fully understand the purpose.

 

Here it is at Idle. I think it just combines processes much the same way Firefox used to compared to Chrome.

 

Hello Dick, *Smile

SvcHostSplitThresholdInKB DWORD is used to reduce the amount svcshost.exe processes by increasing the threshold for when the service processes split.

The default and recommended behavior is having more svcshost.exe processes by leaving the SvcHostSplitThresholdInKB DWORD set to 380000 for the reasons at the top of the tutorial.

 

That makes sense, and is clear now. It's the reverse of what it looks like on the surface. Threshold was the keyword there. Guess you could turn it off completely by using the 64GB value, but why on earth do that! *Smile

Thanks, Shawn!

 

You're most welcome. *Smile

 

I think that the real question was, why to do this?

Well, people thinks they will reduce memory consumption is they leave the old service model. The truth is, that is an illussion, I tried this tweak, and in fact, in my 16 GB system, it reduces RAM usage at boot from 1.4 GB to 1.3 GB (my normal in 1607 build), but as time passes, the RAM usage is being the same as leaving the threshold by default.

Honestly, I woudn't fret this so much if you have more than 4 GB, this won't make any difference, but instead, as I noticed, can make this particular version of windows boot slower. Remember Windows knows how to manage RAM, more in this editions, you won't be run out of memory unless you have 20000000+ programs open.

Still, for the memory freaks, this is a good tutorial, thanks @Brink!

 

Shawn explained it very well in the OP as to why to do it.*Wink

 

Always nice to have more settings to play with just for the sake of it. *Biggrin