It is very important to clearly understand the difference between binary and decimal units :

  • 1 Terabyte (1 TB), decimal unit, according International System of Units (SI) defining metric system is 1.000.000.000.000 (or 1000^4) bytes
    • Used for disk unit labels
    • Used by Apple macOS, IBM i, …
  • 1 Tebibyte (1 TiB), binary unit, according computer scientists is 1.099.511.627.776 (or 1024^4) bytes
    • Used by common storage systems
    • Used by AIX as well as most of Linux and UNIX editions, Windows, …
  • Difference ?
    • A 4.00 TB drive, so 4000.00 GB ?
    • Gives 3725.29 GiB, so 3.64 TiB !

Any misunderstanding may lead to severe disappointment, because with nowadays capacities the difference can be huge.