I recently started to recycle some of my computer technology to make room for some new toys. I've given a couple of desktop systems to my daughter's family for the grandkids to use. The last system I sent over on Sunday had an SSD drive in it that I wanted to keep, so I swapped it for a spare hard drive I had laying around.
While I was at it - crawling around under the desk tracing and retrieving cables and such - I decided to freshen up the main tower system by adding a USB 3.0 interface. At the same time I bought a little USB 3.0 case for the SSD I saved out of the other system. This all makes backing up the system drive on the main tower a much faster process when using an external USB drive. Data transfer is so much faster with the USB 3.0 interface than the USB 2 interface!
I did a test transfer both directions between the SSD in the main tower (Samsung 840 EVO) and the spare SSD (Samsung 840) in the USB 3.0 case on the USB 3.0 port. The transfer speed was identical in both directions (125MB/sec).
That was using the Copy function, dragging and dropping a 450MB file from one drive to the other and clicking on the More Details dropdown in the Copy dialog window. Hardly scientific but it gives a good basis for comparison of relative performance. And it's real world performance, not an artificial benchmark.
Using that same test I found that there are significant differences in USB flash drive performance. I have a 16GB Kingston Data Traveler that I was using to compare the difference between my old USB 2 hub and the new USB 3 interface. My first tests were discouraging.
I'm using hubs because all of the USB interfaces on the main tower are at the back and I have no interest in fighting dust bunnies and cobwebs under the desk every time I want to use a USB device.
Initially I connected the new USB 3 hub to the new USB 3 interface with a 6 ft. USB extender cable I had laying around because the cable on the new hub is only 1.5 ft. long and won't reach the back of the tower. Using the old extender cable turned out to be a mistake.
My initial testing showed that the performance of the Kingston flash drive, which is supposed to be USB 3, was virtually identical using either hub.
In order to eliminate the hub and the extension cable I crawled under the desk and stuffed the flash drive directly into one of the ports on the new USB 3 card. The read speed improved immensely!! It nearly quadrupled.
I have a short extender cable that is specifically for USB 3.0 and it's just long enough to get the USB 3 hub out where I can use it. With the Kingston flash drive plugged into the USB 3 hub on the short USB 3 extender cable the performance was identical to when it we plugged directly into the USB 3 card.
I was really impressed with the read performance of the Kingston flash drive once I got the connections all sorted out. The write speed was another story -- and that's why I decided to write this. The write speed on this particular flash drive (which is sold as USB 3) is no better than a good USB 2 flash drive. The performance is the same whether I test it in the USB 2 hub or the USB 3 hub. I also tested it against a good quality USB 2 flash drive I have and the write performance is identical in either hub.
I checked the specs on Kingston's web site and it was illuminating. This particular model comes in 8GB, 16GB, 32GB, 64GB and 128GB sizes. The product documentation lists a write speed specification for the 32GB and larger models but it does not specify the write speed for the two smaller versions. Now I know why!
This flash drive is only half USB 3. It's a rocket when you read stuff from it. When you have to write anything it's no better than a good quality USB 2 flash drive.
So, two things to take away from this. If you are going to use USB 3 devices on a USB 3 interface and have to use an extender cable and/or a hub to make it practical to use, make sure all the stuff is guaranteed to be USB 3 capable. Otherwise you will only get USB 2 performance.
If you are buying a USB 3 flash drive and the write performance is important, you will need to do some research before purchasing. It looks like read speed is fast on almost any USB 3 product but write speeds are a completely different issue.
...ken...