Review on Gigastone 32GB 5-Pack Micro SD Card: Full HD Video, Surveillance Security Cam Action Camera Drone, 90MB/s Micro SDHC UHS-I U1 C10 Class 10 – Enhanced Storage for Multi-purpose Devices by Deon Sweeney

The USB adapter used makes a big difference in speed. I first tested this card with a USB 2 adapter, which showed around 20MB/s. Pretty good, but far from the advertised 90 MB/s. But when I switched to the new USB 3 mSD memory card adapter, the average read speed increased to 68MB/s. There are many environmental variables that affect the actual achievable speed of a device connected to the bus. Android is always terribly slow when exporting data. Windows depends on system startup, drivers, and specific chipsets, so I didn't expect such a big boost. ALL mSD CARDS ARE FRAGILE. CAREFUL HANDLING. THEY BREAK EASILY. If your speed is slow, there is usually a system problem. On USB2 you should get 10-20MB/s. On USB 3 you can reach 70-80 MB/s. Linux is pushing data transfers ever closer to the theoretical maximum throughput. Windows, you can get half, and Android, well, have a cup of coffee and watch a football game while waiting for the pictures to transfer. Due to the memory organization corresponding to the industry standard, 14.6 GB are available on this card. Some blocks are reserved for file system data and some are reserved to replace bad blocks. That's fine, but note that if you need at least 16GB of storage, you'll need a larger card.