Super-slow LAN speed, unless downloading through Chrome's FTP client

I have connected 2 PCs using ethernet cable and set up FTP on one of them to transfer some >100GB of files. However, trying to download it, I run into a problem of speed not more than 50kB/s. It happens whether I download through Nautilus or Filezilla.

However, if I try to download a large file using Google Chrome, it downloads at speed around 50MB/s, which is pretty good. But Chrome cannot download directories.

What can be a solution to either speed up LAN or download a directory through Chrome?

• UPD: I tried to create a torrent and send it that way, but it's no better, stays around 100kB/s...


• UPD1: I changed the cable and it didn't change, also it stops completely, if I turn on WiFi parallel to the cable.


• UPD2: I found an advise to edit /etc/default/grub to disable IPv6, but it didn't help as well.

A small detail: both sender and receiver file systems are NTFS, does it make a difference?