Intel's iAPX 432 was a very ambitious multi-chip microprocessor architecture introduced in 1981. It was unacceptably slow and did not supplant Intel's x86 architecture as planned.
The project was Intel's first 32-bit microprocessor design, and intended to be the company's main product line for the 1980s. Many advanced multitasking and memory management features were implemented in hardware, leading to the design being referred to as a Micromainframe. "iAPX" stood for intel Advanced Processor architecture.
Originally designed for clock frequencies of up to 10 MHz, actual devices sold were specified for maximum clock speeds of 4 MHz, 5 MHz, 7 MHz and 8 MHz respectively with a peak performance of 2 million instructions per second at 8 MHz.
The iAPX 432 was "designed to be programmed entirely in high-level languages", with Ada being primary. Direct hardware support for various data structures was intended to allow modern operating systems for the 432 to be implemented using far less program code than for ordinary processors; combined with direct support for object-oriented programming and garbage collection, this made the hardware (mostly the microcode part) much more complex than most processors of the era, especially microprocessors.
iAPX 432 systems were expensive and very slow. In 1982, simple benchmark tests ran 4 times slower on iAPX 432 than on the conventional 80286 chip at the same clock frequency. The first generation chipset was a total failure in the market. Intel saw ways to improve a second generation design, but it would still be impractical with large overheads for the capability architecture and instruction set. The plan to replace the 8086-line (later known as the x86 architecture) with the iAPX 432 was abandoned.
The iAPX 432 project was a commercial failure for Intel, to the extent that Intel's corporate website contains no indication there had ever been such a product. Intel's continued development of its x86 line, which the iAPX 432 architecture was meant to replace, was hugely successful.