I have a new laptop with USB 3.0 ports, and a new SATA 5200 rpm hard drive I just put into a new USB 3.0 enclosure.

I am copying my backups from the local hard drive to the new USB 3.0 hard drive/enclosure. It has settled at 26.1 MB/sec.

Is that the speed I should expect, or might something be wrong?


  • The performance you see should be completely controlled by the performance of the hard drive itself. If you tell us the make and model, we can look up the rated and measured performance and see if your numbers are typical. Aug 25, 2011 at 22:40
  • See related question Verifying USB connection speed (USB 3 or USB 2?)
    – Molomby
    Dec 1, 2015 at 1:34
  • This is old, but I'll add, with file transfers, especially external, moving many small files has a huge negative impact on average throughput (5x reduction compared to moving a single large file is not unheard of) So what you are moving can have an equally large impact as the technology. Sometimes zipping or tar can help speed up the overall process.
    – MadHatter
    Apr 4, 2021 at 16:08

7 Answers 7


USB3 operates at higher speeds than SATA can handle, so optimally you should notice no difference between USB3 and an internal drive of the same type. In my experience with my own drive, I've noticed this to be true.

As for exact speeds, SATA 2 operates at 3 Gb/s optimally, which gives a maximum bandwidth of ~384MB/s. SATA 1 operates at 1.5 Gb/s I believe. You won't get anywhere near that with a 5200rpm drive though unfortunately. 25-30MB/s doesn't sound overly low to me.

The best test would be to connect the drive internally and test it there. If it's getting the same sort of performance, then see my first paragraph. If not, then there may be other issues coming into play.

EDIT: Using HD Tune I did a benchmark of my own USB3 drive, which is a caddy providing a RAID1 of two SATA2 5900rpm drives. I'd expect these to operate at about 1.5-1.7 times better than the drive you describe, which is what I got as well. The fact these numbers line up would indicate to me that both our results are in fact capped by the drives in use, not the bandwidth provided by USB3.

HD Tune drive benchmark

  • 1
    While USB 3.0 can theoretically attain 3.2 Gbit/s, I doubt anyone will get even a third of that in practice. SATA is almost always going to be faster.
    – Cajunluke
    Mar 16, 2011 at 0:13
  • @CajunLuke I have a USB3 raid 1 array, and it runs beautifully, I can play games off it at least as well as I can off my older internal SATA 2 drives. I've not noticed any drop in performance at all. While SATA2 can theoretically attain 3.0 Gbit/s, I've never attained that in practice either. Mar 16, 2011 at 0:15
  • @CajunLuke It depends entirely on what you spend on a harddrive. If you buy a $30 SATA1 5200rpm drive, then you have to expect bad performance. Mar 16, 2011 at 0:21
  • Good point. I've always had poor performance with any USB 2 device (haven't used any 3.0 devices yet), so I had little hope for 3.0.
    – Cajunluke
    Mar 16, 2011 at 4:27
  • @CajunLuke added a benchmark for my drive, you may be interested. Mar 16, 2011 at 8:45

It's very likely something is wrong with your USB connection; the speeds you're seeing are at the mid to high end of USB 2.0.

I'd suggest using USB Device Tree Viewer to determine what type of USB connection is actually being established with the device (ie "High-Speed" or "SuperSpeed").

There's a great description of how use USB Device Tree Viewer in this answer, given to a related question of mine.

To paraphrase, select the device you're concerned with and examine the Connection Information to that appears in the right pane.

Devices connected in USB 3.0 "SuperSpeed" mode will report:

Device Bus Speed         : 0x03 (SuperSpeed)

Devices using USB 2.0 will show:

Device Bus Speed         : 0x02 (High-Speed)

I have an external USB 3.0 drive enclosure with a 64GB SSD drive in it. I too get about 25-30MB/s throughput. Sometimes more depending on what is read/written. And it is connected to the USB 3.0 port too.

My USB 2.0 flash drive reads about 5MB/s depending on the data.

I can't find a freeware drive speed tester yet.

While USB 3.0 is about the same rating as SATA2, SATA2 internal drive (conventional) still seems faster.

It would appear that all the drive makers of USB 2.0 and 3.0 outright lie bout the actual real life speeds.

If I got 5GB/s you would hear me scream 1/2 way around the world! LOL

  • 3
    I get well over 100 MB/s to my external HDD via USB (it's a 7200 RPM Western Digital Caviar Blue 1TB). And indeed you should get more too, the bandwidth of USB3 is comparable (and even higher) to SATA-II. Nov 19, 2012 at 1:26
  • I edited some occurrences of megabits to megabytes because I'm fairly sure you're not getting speeds quite that low. And I agree with @Breakthrough: my USB3 speeds are over 100MB/s, even with the mediocre enclosure I'm using.
    – oKtosiTe
    Mar 11, 2013 at 11:44

I just got average 88MB/s using a Rosewill USB 3 external enclosure with a ES.2 Barracuda 32MB cache drive. I think its 5600RPM. I achieved that rate transferring "World of Warcraft" directory off of my SSD. I thought it seemed low but after reading this I'm seeing it was a fair speed.

  • I edited this message from megabits to megabytes, because I'm fairly certain that that's what you meant.
    – oKtosiTe
    Mar 11, 2013 at 11:34

i have a lenovo g680, i bought a new 1tb toshiba external hd with usb 3.0. I get around 48-52 mb/s transfer speed. A usb 3.0 interface can transfer upto 5gb/s but it is mostly limited by internal rives when we copy.


I got a steady slightly above 90MB/s speed when coping more than 300G files from my Toshiba 1G external hard drive to WD 1G external hard drive through USB 3.0 ports on my new HP laptop.


I average around 90 MB/sec transferring 10 or so files totaling 30gb on USB 3.0 to either a mechanical HD or a solid state. Windows 7, i5, 16gb RAM, 1TB and 128G Hard drives.

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