About writing and reading speed ( USB 3.0 reader Test Result):

16GB U1 Class10 speed == Max Read speed to 48 MB/s

32GB U1 Class10 speed == Max Rread speed to 60 MB/s

64GB U3 Class10 speed == Max Rread speed to 80 MB/s

128GB U3 Class10 speed == Max Rread speed to 80 MB/s

256GB U3 Class10 speed == Max Rread speed to 80 MB/s

The above test data are based on the (ATTO Disk Benchmark) test results.

The actual test speed should be based on the level of the card reader or computer excuse.

Ask the buyer to test in the highest possible way.Use USB 3.0 card reader.

And the USB3.0 port for the computer.

(please dont use usb 2.0 card reader to test our card speed ,we have high quality usb 3.0 card reader meet this standard you can buy our card reader .)

16GB=approximately 14GB-15GB

32GB=approximately 28GB-30GB

64GB=approximately 58GB-60GB

128GB=approximately 116GB-120GB

This is calculation difference between manufacturer and our PC, please Google 'Memory card capacity' to get more information.

Please use quaity card reader to verify all memory card by H2testw on PC

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

The most reliable software to verify memory card is H2testw

**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.