microSD

Is a flash memory used in various Hardware such as computer

Icons

Bus speed

• Ultra-High Speed (UHS) Class – represented by a “U” symbol
  • Bus
    • UHS-I: theoretical maximum read/transfer ≤ 104MB/s
    • UHS-II: theoretical maximum read/transfer ≤ 312MB/s
      • Contains 2nd row of pins
    • UHS-II: theoretical maximum read/transfer ≤ 624MB/s
  • Minimum speed: see below table
• SD Express Speed Class – represented by an “E” or "EX" logo, uses PCIe
  • EX I is the bus speed
  • Also uses the 2nd row of pins; but not backward compatible with UHS-II, only UHS-I

Speed Class

Links

• A guide to speed classes for SD and microSD Cards - Kingston
• SD Standard for Video Recording - SD Association
• Bus Speed (Default Speed/High Speed/UHS/SD Express) - SD Association