Terabyte to Word

1 terabyte (TB) = 1,000 gigabytes (GB) in the SI decimal system. In the binary IEC system, 1 tebibyte (TiB) = 1,024 gibibytes (GiB). Consumer hard drives and SSDs are labelled in decimal TB; operating systems may display available space in either GB or GiB depending on the OS and version, leading to a discrepancy of up to ~7% between the label and the OS display.

A 1 TB SSD holds approximately: 200,000 JPEG photos (at 5 MB each), 250 HD movies (at 4 GB each), 200+ modern AAA games (at 50 GB average), or enough for about 100 hours of 4K video footage from a modern camera. In practice, the OS and drive firmware overhead reduce usable capacity to roughly 900–930 GB as reported by the operating system.

A terabyte (TB) = 10¹² bytes = 1,000,000,000,000 bytes. A tebibyte (TiB) = 2⁴⁰ bytes = 1,099,511,627,776 bytes. The TiB is about 9.95% larger. This gap is why a 1 TB hard drive appears as 931 GiB (≈ 0.909 TiB) in Windows. The IEC formally defined TiB in 1998 to eliminate this naming ambiguity.

Timeline depends heavily on use case: continuous 4K video recording fills 1 TB in about 2–3 hours (at 1 GB/min). Typical laptop use (documents, photos, apps) might take 3–5 years to fill 1 TB. A game library of 20 modern AAA titles uses 500 GB–1 TB. Home security camera systems recording 24/7 at 1080p use about 1 TB every 10–15 days per camera.

For most individuals, 1 TB of cloud storage is generous: it holds 200,000+ photos, years of documents, and even video libraries. Google One offers 2 TB for €9.99/month; iCloud offers 2 TB for £6.99/month. Power users — especially photographers and videographers — may need 2–5 TB. Family sharing plans can make 2 TB cost-effective across multiple users.

A word's size depends on the CPU architecture. In x86/x64 (Intel/AMD) documentation: word = 16 bits, DWORD = 32 bits, QWORD = 64 bits. In ARM 32-bit: word = 32 bits. In most modern 64-bit systems (excluding x86 documentation): word = 64 bits. When reading technical documentation, always check the architecture's definition, as "word" is not a universal fixed size.

In Windows API documentation and x86 architecture, a DWORD (Double Word) = 32 bits = 4 bytes, capable of holding values 0–4,294,967,295 (unsigned) or -2,147,483,648 to 2,147,483,647 (signed). DWORD is the most common fixed-width integer type in the Windows API, used for flags, handles, and return codes. The equivalent in modern C/C++ is uint32_t (unsigned) or int32_t (signed).

A CPU's word size determines: (1) the maximum addressable memory — a 32-bit CPU addresses up to 4 GiB (2³² bytes); a 64-bit CPU addresses up to 16 EiB (2⁶⁴ bytes); (2) the precision of integer arithmetic — a 64-bit word handles numbers up to ~18.4 × 10¹⁸ in a single instruction; (3) performance — operations on data smaller than the word size may require extra sign-extension instructions on some architectures.

Modern x86-64 CPUs (Intel Core, AMD Ryzen) have 64-bit general-purpose registers, so their native word size is 64 bits for most operations. However, x86 documentation maintains the legacy definition: "word" = 16 bits, DWORD = 32 bits, QWORD = 64 bits. This creates a confusing terminology mismatch between the architectural naming convention and the physical register size.

Memory alignment means storing data at addresses that are multiples of the data's size. A 32-bit word should be stored at an address divisible by 4 (bytes); a 64-bit word at an address divisible by 8. Misaligned access is either forbidden (causes a CPU fault) or penalised (requires two memory reads instead of one). Compilers automatically align variables; manual struct packing can create misalignment that causes subtle performance issues or crashes on strict architectures.