X64--cygiso May 2026
The x64 ISA, also known as AMD64, was introduced by AMD in 2003 as a 64-bit extension to the x86 ISA. The primary motivation behind this development was to enable computers to address more than 4 GB of physical memory, which was a significant limitation of the 32-bit x86 architecture. The x64 ISA achieved this by increasing the address bus width from 32 bits to 64 bits, allowing for a theoretical maximum of 16 exabytes (16 billion GB) of addressable memory.