Windows Defender (Windows Security) going mad when StreamFab is downloading a movie

colemarc

Hello, StreamFab x64 6.2.2.0 on Windows 10 22H2.

I wrote to support to report that, as seen on Task Manager Details tab, MsMpEng.exe starts to use 30%-40% of CPU when StreamFab is downloading, while StreamFab itself does not use more than 10%.
As soon as I turn off Real-time protection in Windows Sercurity MsMpEng.exe becomes quiet, and as soon as I turn it on MsMpEng.exe starts to use a lot of of CPU.

Support instructed me to add the output folder and the program folder to Windows Security exclusions:

But adding these directories to exclusions did not make any difference.
I believe that exclusions are effective only for virus scanning and they do not impact real-time protection.

So, support is not helping much.
This happens only while StreamFab is downloading. I have several other programs besides StreamFab that download files, but I never observed this behaviour with those programs.
Do you experience the same phenomenon?

Olivierduc

Nothing comparable for me.
When downloading, 3-8% CPU charge for StreamFab, almost nothing for Windows Defender (1-3%).
Windows 10 22H2, CPU Intel i7-12700, RAM 32 GB.

Wilson.Wang

Hi,

Please also add the temp folder to the exclusions list.

Wilson

colemarc

@Wilson.Wang

Already tried:

It does not make any difference:

october262

Hello, StreamFab x64 6.2.2.0 on Windows 10 22H2.

I wrote to support to report that, as seen on Task Manager Details tab, MsMpEng.exe starts to use 30%-40% of CPU when StreamFab is downloading, while StreamFab itself does not use more than 10%.
As soon as I turn off Real-time protection in Windows Sercurity MsMpEng.exe becomes quiet, and as soon as I turn it on MsMpEng.exe starts to use a lot of of CPU.

Support instructed me to add the output folder and the program folder to Windows Security exclusions:

But adding these directories to exclusions did not make any difference.
I believe that exclusions are effective only for virus scanning and they do not impact real-time protection.

So, support is not helping much.
This happens only while StreamFab is downloading. I have several other programs besides StreamFab that download files, but I never observed this behaviour with those programs.
Do you experience the same phenomenon?

colemarc

read this - MsMpEng.exe, also known as Antimalware Service Executable, can use a lot of CPU resources when it scans for malware. This can happen when Windows Defender is scanning for malware, or when the scan gets stuck on certain files.

Why does this happen?

Scanning: MsMpEng.exe scans the entire system in the background for malware.

Outdated hardware: Low CPU cores or outdated hardware can cause the system to lag or crash.
Outdated software: Outdated software and hardware drivers can cause high CPU usage.

Encrypted malware: Encrypted malware running in the background can cause MsMpEng.exe to fluctuate.

Full scan: A full scan running while other programs are open can cause high CPU usage.

How to fix it?

Reschedule scans: Reschedule Windows scans to when the computer is not in use.

Adjust scheduled scan time: Adjust the scheduled scan time for Windows Defender.

Uncheck "run with highest privileges": Uncheck this option in the Windows Defender scheduled scan.

Manually limit file CPU usage: Open the Task Manager, go to the Details tab, locate the file, right click, and select Set Priority.

Germania

It does not make any difference
colemarc

Are you sure your excluded Temp folder is correct?
Looks like Win Temp - but not SF Temp ..
.. default should be c:\users\colem\Documents\DVDFab\StreamFab\Temp
(incoming segments are saved in SF Temp\outputTemp)

Check the path in your SF Settings -> General -> "Temp Directory"

colemarc

read this - MsMpEng.exe, also known as Antimalware Service Executable, can use a lot of CPU resources when it scans for malware. This can happen when Windows Defender is scanning for malware, or when the scan gets stuck on certain files.
october262

Thanks, but I am positive that Windows Defender was not scanning. I know its scheduling.
The culprit is Real-time protection, as I said above.

colemarc

Are you sure your excluded Temp folder is correct?
Looks like Win Temp - but not SF Temp ..
.. default should be c:\users\colem\Documents\DVDFab\StreamFab\Temp
(incoming segments are saved in SF Temp\outputTemp)

Check the path in your SF Settings -> General -> "Temp Directory"
Germania

I will try again ASAP.

colemarc

Are you sure your excluded Temp folder is correct?
Looks like Win Temp - but not SF Temp ..
.. default should be c:\users\colem\Documents\DVDFab\StreamFab\Temp
(incoming segments are saved in SF Temp\outputTemp)

Check the path in your SF Settings -> General -> "Temp Directory"
Germania

Sure enough, that was it.
c:\Users\colem\Documents\StreamFab\StreamFab\Temp solved the issue.

Thanks!