Please don’t use cheap card reader to test Micro SD card, speed of Micro SD card will be reduced by low quality card reader
**Micro SD card speed is greatly affected by card reader, adapter, USB port etc. Low quality device will 100% slow down card speed.
**Up to 40MB/s read speed; write speed lower. Based on internal testing; performance may be lower depending on host device, interface, usage conditions and other factors. 1MB=1,000,000 bytes.