48bits

48bits refers to a data width of 48 bits, equivalent to six bytes. It is used to describe the size of values, addresses, or color components in various computing contexts. A 48-bit value can encode 2^48 distinct values, which is about 281 trillion possibilities.

In storage and addressing, 48-bit addressing has been used for logical addressing of storage devices. ATA/IDE interfaces support LBA-48, allowing addressing of up to 2^48 sectors. With a common 512-byte sector size, this yields up to 2^57 bytes, or about 144 petabytes in decimal terms (equivalently 128 pebibytes). This larger address space helps support modern drives with very large capacities while remaining compatible with older interfaces.

In networking, 48-bit identifiers are standard for MAC addresses in Ethernet and many other networks. A MAC address is typically written as six octets (for example, 00:11:22:33:44:55) and is assigned to network interface hardware by manufacturers, enabling unique device identification on a local network.

In color representation, 48-bit color uses 16 bits per color channel (red, green, and blue). This 16×16×16 channel depth provides higher precision and smoother gradients than the common 24-bit (8 bits per channel) color, and is used in some professional imaging workflows and high-dynamic-range pipelines.

Other uses include 48-bit totals in specialized hardware calculations or legacy cryptographic schemes, where 48-bit data paths or blocks have appeared in older or niche algorithms. In general, 48-bit widths sit between smaller, legacy systems and wider 64-bit architectures, balancing capacity and simplicity for specific applications.