How fast should a transfer between new WD My Book drives be?

I’ve just build a new file server for my home network.

Intel NUC i5, 5th Generation 

Debian 7.8

2 x 4TB WD My Book

During large disk to disk copy operations (from one WD Mybook to the other) I see speeds typically in the 10 - 15 MB/s range, sometimes up to 20.  Sometimes less than 10.

I get similar speeds with a network (Ethernet) to drive transfer.

It doesn’t seem like the speeds I was expecting for USB 3.0.  None of my Windows machines have USB 3, only USB 2, and yet plugging the drives into those machines doesn’t seem to result in different transfer speeds.  It feels like the drives are only connecting to the NUC as USB 2.0 devices.

The Intel NUC has 4 x USB 3.0 ports.  I have tried all of them.  They don’t seem to behave any differently.

The drives are currently ext4 formatted.  Previously they were the default NTFS from the factory, with no apparent difference in performance.

hdparm -t:

 Timing buffered disk reads:  76 MB in  3.04 seconds =  25.03 MB/sec

lsusb:

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 8087:8001 Intel Corp.
Bus 001 Device 003: ID 1058:1230 Western Digital Technologies, Inc.
Bus 001 Device 004: ID 8087:0a2a Intel Corp.
Bus 001 Device 005: ID 1058:1230 Western Digital Technologies, Inc.

lsusb -t:

/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/4p, 5000M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/11p, 480M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/2p, 480M
|__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/8p, 480M
|__ Port 3: Dev 5, If 0, Class=stor., Driver=usb-storage, 480M
|__ Port 4: Dev 3, If 0, Class=stor., Driver=usb-storage, 480M
|__ Port 7: Dev 4, If 0, Class=‘bInterfaceClass 0xe0 not yet handled’, D river=btusb, 12M
|__ Port 7: Dev 4, If 1, Class=‘bInterfaceClass 0xe0 not yet handled’, D river=btusb, 12M

Is this what we’d expect to see?  Or should Dev 3 and Dev 5 be showing up as 5000M devices?

If they’re being incorrectly recognized as USB 2.0 devices, how can I fix it?

Hi RevMen, welcome to the Community. Linux is not a supported OS so you might run into some problems. On Windows computers I usually recommend to have the latest USB 3.0 drivers installed. Let’s see if there are other users that can give you some Linux advice. 

jubei04 wrote:

Hi RevMen, welcome to the Community. Linux is not a supported OS so you might run into some problems. On Windows computers I usually recommend to have the latest USB 3.0 drivers installed. Linux is not a supported OS so you might run into some problems.

While it would be nice to get some Linux advice, as you can see by the content of my post and the title of the thread, what I’m most interested in knowing is whether the speeds I’m seeing are what I should be expecting.  That seems like an OS-independent question.