The rate is for data storage on PC Port for my needs perfectly fine. In automotive, there was also no speed problems with MP3 files .. The memory card can also be used for embedded systems with microcontrollers. Again, there was not a single problem with the memory card (I work with it every day). In a small card reader controller is actually built, so it is not just a passive adapter. For this price you can not complain really. However, I had only two (out of ten) dispose card reader, because they were recognized by now equal to any port more. The cards were not defective. Still BUY recommendation ... maybe it was just bad luck.