I am currently using a Retina MacBook Pro 13" (512GB SSD, 8GB RAM, Early 2015). It's connected via Wi-Fi (5GHz) to Asus RT-AC67U (AC2400) Router in which a Seagate Expansion 2TB (4 Partitions; Main partition is HFS+ formatted for samba share) is connected physically via USB 3.0 to the router.

When I am connected to my Seagate locally via USB 3.0, transfer speeds are good and normal, however when I connect via network wirelessly, I often see the beachball icon on my Mac, even to open a MPEG-4 video file, it takes a lot of time, basically transfer speeds are about 400Kbps as opposed to 20-30Mbps.

When I am connected to my router physically via ThunderBolt Ethernet, the speeds are absolutely fine. Could this be a Wi-Fi problem then?

1 Answer 1


Looks like this could be caused by an SMB3 signing default change introduced in OS X 10.11.5. It can be overridden by adding or modifying a file in your /etc directory. See the thread El Capitan 10.11.5 update SMB slow (bug) in the Apple support community for the whole story.

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