Samba server

sudo apt-get install samba
sudo mkdir -m 1777 /media/unencrypted_drive/SharedFolder
sudo chown pi:pi /media/unencrypted_drive/SharedFolder

Put the following at the end of /etc/samba/smb.conf:

[global]
   smb encrypt = off

...

[RaspberryPiShare]
	path = /media/unencrypted_drive/SharedFolder
	public = no
	writeable = yes
	browsable = yes
	create mask = 0777
	directory mask = 0777

Setup credentials:

sudo smbpasswd -a pi

Then:

sudo systemctl restart smbd

Tips:

Use ext4 file system if using Linux.
Connect RPi with router through an Ethernet cable. Make sure the cable supports gigabit connections, otherwise overall throughput won’t go above 100 Mbps.