↑ abEven though this is Microsoft's stated minimum processor speed for Windows XP, it is possible to install and run the operating system on early IA-32 processors such as a P5Pentium without MMX instructions. Windows XP is not compatible with processors older than Pentium (such as 486) or the Cyrix 6x86 because it requires CMPXCHG8B instructions.
↑ abA Microsoft TechNet paper from Summer 2001 (before Windows XP's actual release), states that: "A computer with 64 MB of RAM will have sufficient resources to run Windows XP and a few applications with moderate memory requirements." (Emphasis added.) These were said to be office productivity applications, e-mail programs, and web browsers (of the time). With such a configuration, user interface enhancements and fast user switching are turned off by default. For comparable workloads, 64 MB of RAM was then regarded as providing an equal or better user experience on Windows XP with similar settings than it would with Windows Me on the same hardware. In a later section of the paper, superior performance over Windows Me was noted with 128 MB of RAM or more, and with computers that exceed the minimum hardware requirements.
