Intel manufactured the original Xbox’s Pentium III-based processor.
The original Xbox used a custom version of Intel’s Coppermine Pentium III processor, running at 733 MHz. Microsoft paired this x86-based CPU with a custom Nvidia graphics processor, giving the console a hardware design that differed from the PowerPC-based architectures used by several competing systems of the era.
The processor’s Intel heritage is one reason the original Xbox was comparatively familiar to PC developers. Its architecture supported the console’s operating system, game engines, and features such as online play through Xbox Live. However, the Xbox was not simply a desktop computer in a console case: Microsoft and Nvidia customized important components and the system software.
This fact is sometimes mixed up with the Xbox 360, whose processor was designed by IBM, or with later Xbox consoles, which used AMD-based custom processors. The original Xbox therefore marks the only main Xbox generation built around an Intel CPU.