Very slow transfer speeds even when external drive is connected directly (USB) to EX2


I have a WD My Book 4 TB USB 3.0 HD

I recently bought the EX2, and I’m trying to transfer files from the My Book to the EX2.  Right now I have the My Book connected via USB port 1 on the EX2, both plugged in.  I selected all folders on the My Book, selected copy, pasting into a folder on the EX2.

It’s been going for nearly an hour, transfer rate reads at 4.03 MB/sec.  The My Book is nearly full.  If I’m calculating correctly, this is going to take something like 10 (!) days?  I’m pretty sure either or both of the devices will overheat and crash before then.

What is going on with this very slow transfer rate?  How can I improve it?

I had the My Book connected to my PC previously, transfer rates from the PC HD to the My Book were never ever this slow.

Any advice appreciated!  I think I’m going to have to cancel this copy for now until I figure out what’s going on.

I have a 4TB My Book connected to my EX2 as well. When you copy between EX2 and the My Book (in either direction), it matters on which computer you issue the copy command. IF you issue copy command on the EX2 itself (EX2 is a computer) after logging into it via SSH, then the copy will be blazingly fast, utilizing the USB 3 connection to it. But on the other hand if you open the source folder on My Book and the target folder on the EX2, on a Windows laptop and then copy the files using Windows, then you are basically issuing the copy command on the Windows computer. In that case, you are routing the data from My Book to your Windows computer and then to the EX2, essentially adding an unnecessary round-trip to your computer’s network card before it goes to it’s destination…because the Windows computer is doing the data routing. And it gets worse when your Windows (or Mac) computer that’s serving as this intermediary, is only connected to the network via a wireless connection, and not a wired connection. The speed you posted (~ 4MBps) is very typical speed of Windows computer on a wifi network connected on an N (802.11n) router. You can get much better speeds anytime you connect your computer to the network using a wired connection (CAT 5/6 ethernet cable…preferably CAT 6). You will get the best speed when you don’t do this copy operation in Windows, but instead login to the EX2 via SSH, navigate to the share you are copying (usually they are in a path like /mnt/HD/HD_a2/<your_share_folder_name>) and then copy from the path on the USB depending on which USB port you connected the drive to, it will either be /mnt/USB/USB1_c1 or /mnt/USB/USB2_b1. Of course, you need to be comfy with simple Linux/Unix commands like copy command…if you aren’t Google is your best friend.

If this answers your question and sets you on your way to resolve your issue, kindly click the star on the left of this post under my username to give me a kudo for helping you…and mark this post as a solution, so that other users can benefit from this.

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Thanks, Cybernut1.  Very well explained.

I picked up a CAT6 cable today and currently have it connecting my PC to my router.  Attempting another copy, now I’m seeing probably 30 -50 MB/s.  So it looks like copying is still going to be an overnight deal but that is like 10x faster.

I’m not familiar with SSH linux commands, I’ll look into that later.  For the short term I’ll probably keep the cable running until I get everything backed up, then disconnect and go back to wireless (the cable is a bit ugly running across my baseboard 15 feet from PC to router.)

Thanks again for your help!