I have quite a lot of Micro SD cards, USB Sticks and various portable storage devices. Recently I needed to give someone a file, so I stuck it on a Micro SD card,
and passed it over to them for them to copy.
The file was around 1.2gb, and they said it was going to take 22 minutes to copy to their machine. I thought this seemed a long time, even though it was a 'class 1' Micro SD.
This got me thinking about the whole speed of SD cards, adapters, USB sticks, etc. etc.

As I had quite a bit of time on my hands (fat chance), I decided to do a bit of testing. My laptop has a USB 3 port, as well as a couple of USB 2 ports and a built-in SD card reader. I also had:-
1 Transcend USB 3 card reader
1 USB 2 card reader
1 Kingston Micro SD Card Reader
1 Generic Micro SD Card reader
1 USB 3 64gb Memory Stick
1 USB 2 4gb Memory Stick
1 Sandisk Ultra 32gb Class 10 Micro SD card
1 Sandisk 2gb Class 1 Micro SD Card
1 Samsung 32gb Class 10 SD Card

To do my testing, I used the excellent HD Tune, and because I had data on most of the cards, I only did read test. The table below summarises the results.

 

Card Type	Card Size	Manufacturer	Class	Interface	Read Speed MB/s	Access Time ms
Micro SD	32gb	Sandisk	10	Transcend USB 3 Reader	41.7	0.845
SD Card	32gb	Samsung	10	Transcend USB 3 Reader	41.4	0.587
SD Card	32gb	Samsung	10	USB 2 Reader	23.2	0.582
Micro SD	2gb	Sandisk	1	Transcend USB 3 Reader	21.8	0.797
SD Card	32gb	7DayShop	10	Transcend USB 3 Reader	21.7	0.904
Micro SD	2gb	Sandisk	1	Built-in Reader	19.1	0.585
SD Card	32gb	7DayShop	10	USB 2 Reader	18.5	1.14
Micro SD	32gb	Sandisk	10	Kingston USB 2Adapter	17.6	1.04
SD Card	32gb	7DayShop	10	Built-in Reader	17.1	0.729
Micro SD	2gb	Sandisk	1	Kingston USB 2 Adapter	17.1	0.838
SD Card	32gb	Samsung	10	Built-in Reader	15.8	0.409
Micro SD	2gb	Sandisk	1	Generic USB 2 Adapter	0.9	1.55
USB3 Stick	64gb	7DayShop	?	USB 3 Stick	71.7	1.08
USB3 Stick	64gb	7DayShop	?	USB 3 Stick in USB 2 Slot	29.2	1.3
USB2 Stick	4gb	Generic	?	USB2 Stick in USB 2 Slot	26.7	0.755
USB2 Stick	4gb	Generic	?	USB2 Stick in USB 3 Slot	28.7	0.571

 

 

As with most things in this life, you get what you pay for. The 'generic' Micro SD card readers were 2 for 99p, whereas the Kingston Micro SD Card Reader was £4.99

The figures are quite revealing - the Transcend USB 3 reader that I paid around £10 for performs really well - well worth the money. The USB 3.0 Memory Stick in the USB 3.0 port is the best performer, as you would expect, but the Transcend is great for the money. The generic Micro SD readers are OK if you want to give someone a small text file, but if you want to move a big file, forget it.

In the past, I have actually run a Virtual Machine on a 64gb USB 3 stick in a USB 3 port - and it worked well.

Moral of the story - you DO get what you pay for when it comes to SD adapters - the 2 for 99p seem a bargain, but splash out a bit more the for a named brand.

Originally posted 29/Aug/2013