I have shared a folder on my Debian 8 GNU/Linux PC using Samba network sharing service. The folder is on an external hard disk that is connected to the PC using an USB 3.0 cable. The PC is connected to a Linksys x3500 router using a CAT6 LAN cable which the PC reports that it has 1 Gbps connection speed. I have also a Lenovo X1 Carbon laptop and I want to copy a shared file into it.
I checked this file transfer using a LAN cable which is reported to have 1 Gbps connection speed. The copy has approximately 30 Mega Bytes per second speed. Then I checked it using Wi-Fi with 5 GHz frequency which is reported to have 300 Mbps connection speed. The copy has around 3 Mega Bytes per second speed.
I changed the Wi-Fi configurations in the router like Channels and 802.11n Rate but they are all the same.
Why is my Wi-Fi connection so slow? How can I speed it up?