Why does unpacking tar archives slow down in Windows?

Question

Data archiving

Good afternoon.
Given:
OS: Windows Server 2012
~500 MB tarballs on average with text files downloaded from ftp.
Number of archives ~50
Task:
It is necessary to download from ftp, unpack certain files from the archive. And you need to do this on the instructions of the windows scheduler.
Tried tar, now I'm testing 7z archiver.
The problem is that it unpacks quickly at first. But after 2-3 unpacking, unzipping starts to run slower. Please tell me what it can be connected with, and whether it can be accelerated.

Answer 1

Tar is an uncompressed archive. The name of the files and their contents are stupidly stored there, without any compression. So only folders (FS) overflowing with files or some kind of antivirus or indexing that cannot cope with such a flow of information can slow down.