In computer architecture, 128-bit integers, memory addresses, or other data units are those that are at most 128 bits 16 octets wide. Also, 128-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size.
There are currently no mainstream general-purpose processors built to operate on 128-bit integers or addresses, though a number of processors do operate on 128-bit data. The System/370, made by IBM, could be considered the first rudimentary 128-bit computer as it used 128-bit floating point registers. Most modern CPUs feature SIMD instruction sets (SSE, AltiVec etc.) where 128-bit vector registers are used to store several smaller numbers, such as four 32-bit floating-point numbers, and a single instruction can operate on all these values in parallel. These are 128-bit processors in the sense that they have 128-bit registers, but they do not operate on individual numbers that are 128 binary digits in length.
There are currently no mainstream general-purpose processors built to operate on 128-bit integers or addresses, though a number of processors do operate on 128-bit data. The System/370, made by IBM, could be considered the first rudimentary 128-bit computer as it used 128-bit floating point registers. Most modern CPUs feature SIMD instruction sets (SSE, AltiVec etc.) where 128-bit vector registers are used to store several smaller numbers, such as four 32-bit floating-point numbers, and a single instruction can operate on all these values in parallel. These are 128-bit processors in the sense that they have 128-bit registers, but they do not operate on individual numbers that are 128 binary digits in length.
