We only use original Samsung, Hynix,Intel or Micron flash memory chips,We never do upgrade, and use fake or ... , reading speed 7-13 MB /s and writing speed 3-7 MB /s. (depends on flash chip use flash and computer configuration).6. ... different order quantity, packaging and printing requirement, USB Flash Drive capacity and fluctuations in Flash Memory Chips for original Samsung / Hynix / Micron / ...