64-bit computing
Computing that uses 64-bit data types or processor registers, enabling operations on 64-bit values and larger address spaces than 32-bit systems.
CPU register: A small, fast storage location inside a processor used to hold data, addresses, or instruction state. A 64-bit register can hold a 64-bit value in one processor location.
x86-64: A 64-bit extension of the x86 instruction set used by most desktop and server processors. It brought 64-bit registers and expanded addressing to the widespread x86 platform.
32-bit computing: Computing based on 32-bit processor registers, data types, or address formats. It offers a smaller directly addressable range and narrower native values than many 64-bit systems.
Physical Address Extension: An x86 memory-management feature that lets 32-bit systems address more physical memory than a 32-bit address alone permits. It shows that larger physical memory capacity does not always require 64-bit software.
Binary number: A number represented using the two digits 0 and 1. A bit is one binary digit, and 64 bits encode a fixed number of binary patterns.
Instruction set architecture: The specification of a processor’s instructions, registers, data types, and rules for executing programs. It defines which 64-bit operations and registers a processor exposes.
AArch64: The 64-bit execution state of the Arm architecture, used in phones, computers, and servers. It is a major alternative 64-bit architecture across mobile and general-purpose computing.
Address space: The set of memory addresses available to a process, device, or computer architecture. Address-space limits depend on address width, but also on hardware and operating-system design.
Memory overhead: Memory consumed by metadata, alignment, and representation choices rather than a program’s underlying payload. Wider pointers and alignment can make some 64-bit programs use more memory.
Bit: The basic unit of digital information, with two possible values, usually written as 0 or 1. The “64” counts binary information positions in a value or register.