Long time forum forager, first time poster.

I bought a Toshiba 500 GB usb 3.0 hard drive last week and instantly ran home to see how fast I could push it. On my desktop (that I built) I was able to get 200 MB/sec. On my laptop (MSI FX something or other), which I dual boot Windows 7/Ubuntu 11.10, I was able to get about 120 MB/sec on Windows, but on Ubuntu, i get about 25 MB/sec.

lsusb shows:

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:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 003: ID 0bda:0139 Realtek Semiconductor Corp.
Bus 002 Device 003: ID 1532:0015 Razer USA, Ltd
Bus 004 Device 002: ID 0480:a007 Toshiba America Info. Systems, Inc.

lspci -vvv shows that the USB 3.0 host controller is using the kernel driver in use is xhci_hcd.

dmesg |grep usb shows:

[ 1815.455368] usb 4-1: new SuperSpeed USB device number 2 using xhci_hcd
[ 1815.475459] scsi7 : usb-storage 4-1:1.0

The built in disk utility says its connected via usb at 705 MB/s, but that's not what it reports when I transfer files over to it.

Not really sure what to do at this point. Any help would be very nice.

  • 1
    you would expect slower speeds if you are accessing a FAT32/NTFS external partition. What are you using? Have you tested against a ext4 partitioned external drive?
    – fossfreedom
    Mar 5, 2012 at 23:11
  • 1
    @fossfreedom - It would be good to put your comment as an answer since it not a common thing to know that. It will help more users when they come with the same problem and see this info. Mar 6, 2012 at 15:42

1 Answer 1


When accessing an external USB hard drive formatted in FAT/NTFS, even though it's V3.0 compliant, transfer speed might be slower than what's expected. I tested with a Western Digital 500 GB v3.0. If you're the only one using this e-HDD, format it to EXT4, that's way better and transfer speed should increase.

To benchmark Read/Write rates for your HDD (or EHDD, External Hard Disk Drive), you can use the Disk Utility (Install it, from Software center). You can run it then, from Terminal using the command: gnome-disks (previously known as palimpsest).

Beware that the Write Benchmark tests require your HDD to be empty.


Note: Use the same files if you benchmark speed between MS Windows and Ubuntu. And use a reliable tool in MS Windows to get accurate transfer speed information (I wouldn't even use the utility provided by the HDD vendor). Don't rely on the info displayed on the transfer dialog when copying files to or from your HDD, they're usually incorrect.
Also, 705 Mb/s is a big marketing lie.

  • 5
    Yet the 705 Mb/s number is actually correct, too. The marketing deception is in the units used. 705 Mb/s ~= 84 MiB/s. Sep 16, 2014 at 23:28
  • @AJMansfield That is false, the marketed USB 3.0 speed is 5 Gbit/s which equates to 625 MB/s.
    – F.Webber
    May 7, 2019 at 22:22
  • @F.Webber Bus speed has nothing to do with it, the limiting factor is the disk speed. May 7, 2019 at 22:25
  • Where did you get that the Write-benchmark of gnome-disks require the HDD to be empty? Usually is non-destructive Sep 30, 2022 at 16:40

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