Obsolescence
The AMD Am5x86, up to 133 MHz, and Cyrix Cx5x86, up to 120 MHz, were the last 486 processors that were often used in late generation 486 motherboards with PCI slots and 72-pin SIMMs that are designed to be able to run Windows 95, and also often used as upgrades for older 486 motherboards. While the Cyrix Cx5x86 faded quite quickly when the Cyrix 6x86 took over, the AMD Am5x86 was important during the time when the AMD K5 was delayed.
In the general purpose desktop computer role, the 486s were used as budget machines for people who could not afford the latest computers, until around 2001, when Windows 95 support ended and Windows 98, ME, 2000, and XP required much more powerful computers to perform well.
Although the 486 became obsolete for personal computer applications by the mid-1990s, Intel had continued production for use in embedded systems. In May 2006 Intel announced that production of the 80486 would stop at the end of September 2007.
Read more about this topic: Intel 80486