USB3 vs USB2 transfer speed test

[ricktas]

As I purchased a USB3 card reader this week, decided to test it out for the first time this evening.

What I copied was 160 Nikon NEF files totaling 2.13GB of data.

* I used my old Lexar USB2 card reader plugged into a USB2 port on my computer
* I used my new Sandisk USB3 card reader plugged into a USB3 port on my computer

I copied the same 160 NEF files off the cards, to the same directory on my HDD on my computer.

The results:

The USB2 card reader copied the files in 2 minutes 49 seconds
The USB3 card reader copied the files in 2 minutes 5 seconds.

I found these results rather interesting, in that USB3 specs should be much faster than USB2, but real-world testing (at least for me) shows that whilst faster, the transfer speed advantage is not as significant as I expected.

[KeeFy]

Odd.

187 RAW files. 4.3GB. SanDisk 60MB/s 32GB CF card.

USB 3.0 Lexar Card reader: 35MB/s 2 min 10 seconds.

Internal Sony USB2.0 Card reader: 22 MB/s 3min 20 secs

Cheap USB 2.0 Card reader: 11 MB/s 6 min 35 secs.

USB 3.0 Wins hands down. Copying to my ssd or HDD makes no difference.

[Bennymiata]

It might be the card you're using Rick, that is causing the slow down.

USB3 should be able to outpace most cards.

[Steve Axford]

The speed of transfer is governed by several factors, only one of which is the path transfer rate. The other factors major factors are the controllers that feed the path. We can assume that the controller at the PC end is fast, but the controller in the card may not be. So, if it is slow, then that will control the xfer speed. It's like attaching a really big pipe to a garden hose. The garden hose controls the flow rate.