Fast change of NTFS rights?

Hello

I have a folder with million of files and a have to change several access rights.
I tried it ones via the windows explorer. This process took over 10 hours.
Is there any possibility (maybe with powershell) to change NTFS rights much faster?

You might be able to achieve faster times by using jobs or runspaces. You are likely to be bound by access to the MFT which is where all the meta data including permissions are stored for files.

What about commands such as cacls or icacls? Have you looked into that?

I have minimal experience with this and found command line vs gui did not save much time in the end. Saving 1-2 hours on a 10hour job was not a big improvement IMO.
The biggest factor in performance is to make changes as close to the file system as possible, on the same host etc.