Gigabyte to Byte

Hard drive manufacturers measure 1 TB as 1,000,000,000,000 bytes (decimal). Windows displays storage in gibibytes (binary) but historically labelled them as "GB" — so 1,000,000,000,000 bytes ÷ 1,073,741,824 ≈ 931 GiB, which Windows displayed as "931 GB". macOS (since 10.6) correctly reports the same drive as "1 TB" using decimal GB. The drive is not lying; the OS was using a binary unit with a decimal label.

8 GB RAM is the current minimum for gaming; 16 GB is the recommended standard for most modern games at 1080p and 1440p; 32 GB benefits heavily multitasking systems or games with large open worlds. Memory-intensive tasks like video editing, 3D rendering, and running large language models locally typically require 32–64 GB or more.

A 4K movie in H.264 or H.265 encoding is typically 50–100 GB on Blu-ray; streaming services compress aggressively to 15–25 GB for 4K HDR content. Netflix's 4K streams average about 7 GB per hour; the downloaded version via the Netflix app for offline viewing is roughly 3–6 GB per hour at high quality settings.

1 GB of mobile data supports roughly: 2–3 hours of music streaming, 1 hour of HD video streaming, 2–3 hours of web browsing, or 30–60 minutes of video calling. Social media apps with autoplay video are heavy consumers — TikTok and Instagram Reels can use 300–600 MB per hour of active use.

AI model sizes vary enormously. GPT-2 (2019) is about 1.5 GB; Llama 2 7B is roughly 13 GB in float16 precision; Llama 2 70B is about 130 GB. GPT-4-class models are estimated at 500+ GB. Quantised (compressed) versions are smaller: a 4-bit quantised 7B model fits in about 4 GB, runnable on a modern laptop. Training requires far more — the training dataset, gradients, and optimizer states for a 70B model can occupy 1–2 TB of GPU memory across a cluster. The trend toward larger models is driving consumer GPU memory from 8 GB to 16–24 GB as a baseline for local AI inference.

A byte contains exactly 8 bits. This is the universal modern standard, though early computing used variable byte sizes (5, 6, or 7 bits). The 8-bit byte became universal with the IBM System/360 in 1964. Eight bits allow 256 possible values (0–255), sufficient to encode all ASCII characters with room for control codes.

Eight bits became standard because it is the smallest power of two that can encode all 128 ASCII characters (7 bits) with a spare bit for parity checking or extended character sets. It also maps cleanly to two hexadecimal digits (0x00–0xFF), making it convenient for low-level programming and hardware design. Earlier systems used 6-bit or 7-bit bytes; 8-bit won due to IBM's dominance in the 1960s–70s.

A nibble (also spelled nybble) is 4 bits — half a byte. A nibble represents exactly one hexadecimal digit (0–F). The term is used in low-level programming, embedded systems, and BCD (binary-coded decimal) encoding. It is not an SI unit and rarely appears in general computing contexts outside of hardware and systems programming.

It depends on the character and encoding. In UTF-8 (the dominant web encoding): ASCII characters (A–Z, 0–9) use 1 byte; common European accented characters use 2 bytes; most Asian scripts (Chinese, Japanese, Korean) use 3 bytes; emoji and rare characters use 4 bytes. A plain English text file is efficiently encoded as 1 byte per character in UTF-8.

In most modern usage, byte and octet are synonymous — both mean 8 bits. "Octet" is preferred in networking standards (RFC documents, ITU specifications) to avoid ambiguity from early computing where byte sizes varied. Internet protocol headers are specified in octets; operating systems and storage devices use bytes. In practice you will encounter "octet" mainly in formal networking documentation.