Abnormally low read/write performance with Samsung MicroSD card topic

So I bought this SD card: http://www.samsung.com/uk/consumer/m...ro/MB-MGCGB/EU
Running A1 SD Bench I got speeds of 12MB/s and 3.8MB/s when it should be close to 70MB read and 20MB/s writes.

Any reason why it could be running that slow other than a faulty drive? Is there something I can do do improve this? :(