So the write speed of 50Mb given / sec. is not ereicht far. It also does not matter if formatted with FAT / FAT32 / NTFS or. The writing speed is between 16.7 Mb / sec. and 17.8 Mb / sec. with USB2 adapter or card reader directly to the PC. With USB3 adapter it rises almost imperceptibly to 19.2 Mb / sec. Since there were going faster Micro cards for less money.