The 32-bit 80386 can correctly execute most code intended for the earlier 16-bit processors such as 8088 and 80286 that were ubiquitous in early PCs. (Following the same tradition, modern 64-bit x86 processors are able to run most programs written for older x86 CPUs, all the way back to the original 16-bit 8086 of 1978.) Over the years, successively newer implementations of the same architecture have become several hundreds of times faster than the original 80386 (and thousands of times faster than the 8086).[4] A 33 MHz 80386 was reportedly measured to operate at about 11.4 MIPS.[5]
The 80386 was launched in October 1985, but full-function chips were first delivered in the third quarter of 1986.[6][7] Mainboards for 80386-based computer systems were cumbersome and expensive at first, but manufacturing was rationalized upon the 80386's mainstream adoption. The first personal computer to make use of the 80386 was designed and manufactured by Compaq[8] and marked the first time a fundamental component in the IBM PC compatible de facto-standard was updated by a company other than IBM.