Intel i486

The Intel i486 is the successor to the i386. It was released in 1989 and was similar to the 386, but the improvements were such that it was twice as fast at a given frequency.

The first 486s were made with a 1 ┬Ám process and incorporated 1.2 million transistors. They were first available as 25 MHz parts, and frequencies up to 100 MHz were made available later. AMD also manufactured i486 clones, with frequencies up to 150 MHz in their 5x86 line (some references mention a 160 MHz model but we are not sure if it really exists, the 150 MHz appear extremely rare and 133 ones are commonly found).

Like the 386s, the 486s had several suffixes:

When not soldered, 486s were installed in Sockets 1, 2, or 3.

There were also OverDrives, which allowed to upgrade a lower mutiplier 486, either by installing it on another socket (ODP486) or by replacing it directly (ODPR486).

Intel A80486-25 Intel A80486DX-50 Intel A80486DX2-50 Intel A80486DX4-100
  • An A80486-25 SX249. Bottom. USA, 1989 Week 41.
  • An A80486DX-50 SX710. Bottom. 1992 Week 51.
  • An A80486DX2-50 SX641. Bottom. 1993 Week 13.
  • An A80486DX4-100 SX900. Bottom. 1994 Week 20.
Intel A80486SX-33 Intel A80486SX2-50 Intel ODP486SX-25
  • An A80486SX-33 SX680. Bottom. 1993 Week 11.
  • An A80486SX2-50 SX845. Bottom. Malaysia, 1994 Week 27.
  • An ODP486SX-25 SZ800. Bottom. 1993 Week 27.
Intel 386 and 486 Keychain Intel 386 and 486 Keychain Intel 80486DX4 Wafer Intel 80486DX4 Wafer Intel 80486DX4 Wafer
  • A Keychain with a 386 Die on one side and a 486 Die on the other.
  • A 6" Silicon Wafer of Intel 80486DX4 Chips. More Views: 1b, 2, 3a, 3b, 3c, 4a.

The i486 is suceeded by the original Pentium in 1993.

Intel i487SX Coprocessor

The Intel i487SX coprocessor was released in 1991 and could be paired with an i486SX in order to provide its missing FPU. It was actually a fully working and modified 486DX that took over the 486SX when installed. Some motherboards are even able to use a 487 as a normal 486DX!

Intel A80487SX
An A80487DX SZ494. Bottom. USA, 1991 Week 25.

Operating System Support