Nibble to Tebibyte

A nibble is 4 bits, or half a byte. It encodes one hexadecimal digit (values 0–15, represented as 0–9 and A–F). Nibbles are important in BCD (binary-coded decimal) encoding, where decimal digits are packed two per byte (each digit occupying one nibble). Packed BCD is used in financial systems and legacy databases to represent decimal numbers without floating-point rounding errors.

Hexadecimal (base 16) maps perfectly to nibbles because 4 bits can represent exactly 16 values (2⁴ = 16). One byte = two nibbles = two hex digits. A byte value of 0xFF (255 in decimal) is two nibbles: F (1111) and F (1111). This mapping makes hexadecimal the natural notation for expressing binary data — programrs use hex because one hex digit always represents a fixed number of bits.

Binary-Coded Decimal (BCD) encodes each decimal digit (0–9) as a 4-bit binary value (nibble). Two decimal digits fit in one byte using "packed BCD". For example, the decimal number 47 is stored as 0100 0111 in packed BCD — each nibble holds one digit. BCD avoids the rounding errors of binary floating-point, which is why it is used in financial software, calculators, and legacy banking systems.

A nibble = 4 bits (1 hex digit). A byte = 8 bits (2 hex digits, 2 nibbles). A word = typically 16, 32, or 64 bits depending on the processor architecture (see the "word" unit for details). These are the fundamental granularities of digital data: nibble for hex/BCD, byte for text and addressing, word for native processor arithmetic.

Nibbles are rarely referenced directly in modern high-level programming but remain fundamental at the hardware level. Embedded systems, FPGA design, network packet parsing, and hardware description languages (VHDL, Verilog) regularly manipulate nibbles. The nibble is also the key concept behind hexdump utilities — the canonical way to inspect raw binary files and network packets.

TB (terabyte) = 10¹² bytes = 1,000,000,000,000 bytes (SI decimal). TiB (tebibyte) = 2⁴⁰ bytes = 1,099,511,627,776 bytes (IEC binary). TiB is 9.95% larger. The practical consequence: a 1 TB hard drive (decimal) holds 0.9095 TiB. This 10% gap is the primary reason drive capacity appears lower in the OS than on the box.

ZFS and Btrfs are copy-on-write filesystems designed for TiB-scale pools with built-in features that traditional filesystems lack. ZFS supports inline deduplication — a 10 TiB pool with 40% duplicate data might show 6 TiB of logical usage but only consume 3.6 TiB physically. Btrfs offers transparent compression (zstd), where a 4 TiB dataset of compressible log files might occupy only 1–2 TiB on disk. Both support snapshots that initially consume zero extra space, growing only as data diverges. These features make "used space in TiB" surprisingly complex to report accurately.

Yes. Linux tools (df -h, lsblk) display storage in IEC binary units: KiB, MiB, GiB, TiB. df -h output showing "1.8T" for a 2 TB drive is reporting 1.8 TiB. Modern Linux distributions correctly label these as TiB in technical contexts. This is one of the areas where Linux is more technically precise than Windows or consumer storage labels.

RAID arrays lose capacity to redundancy: RAID 1 mirrors two drives (50% efficiency); RAID 5 loses one drive worth of capacity; RAID 6 loses two drives. A 4-drive RAID 5 array of 2 TB drives has 3 × 2 TB = 6 TB raw usable (decimal), ≈ 5.46 TiB, minus filesystem overhead. Enterprise storage also reserves space for spares, snapshots, and wear levelling, further reducing usable TiB.

No. A tebibyte (TiB) = 2⁴⁰ bytes = 1,099,511,627,776 bytes — about 1.1 trillion bytes. Exactly one trillion bytes = 10¹² bytes = 1 terabyte (TB, decimal). The tebibyte is approximately 10% larger than a trillion bytes. "Terabyte" is often casually used to mean "1 trillion bytes"; "tebibyte" is the precise binary equivalent at 1,024 gibibytes.