Editing I386 (section)

===={{anchor|The 80386SX variant}}  80386SX====
<!-- [[File:Intel386sx a 50 Kc.jpg|right|thumb|80386SX 16 MHz]]
[[File:i386SX.jpg|200px|right|thumb|A surface-mount version of Intel 80386SX processor in a [[Compaq]] Deskpro computer. It is non-upgradable unless hot-air circuit-board rework is performed]]
[[File:Intel 80386 SX die.JPG|200px|right|thumb|[[Die (integrated circuit)|Die]] of Intel 80386SX]]
[[File:80386SL processor from 1990.jpg|200px|right|thumb|i386SL from 1990]] -->

In 1988, Intel introduced the '''80386SX''', most often referred to as the '''386SX''', a cut-down version of the 80386 with a 16-bit data bus, mainly intended for lower-cost PCs aimed at the home, educational, and small-business markets, while the 386DX remained the high-end variant used in workstations, servers, and other demanding tasks. The CPU remained fully 32-bit internally, but the 16-bit bus was intended to simplify circuit-board layout and reduce total cost.{{efn|This was a similar approach to that used by Intel with the [[Intel 8088|8088]], a derivative of the Intel 8086, that was used in the original IBM PC.}} The 16-bit bus simplified designs but hampered performance. Only 24 pins were connected to the address bus, therefore limiting addressing to 16&nbsp;[[Megabyte|MB]],{{efn|The 16 MB limit was similar to that of the [[Motorola 68000|68000]], a comparable processor.}} but this was not a critical constraint at the time. Performance differences were due not only to differing data-bus widths, but also due to performance-enhancing [[cache memory|cache memories]] often employed on boards using the original chip. This version can run 32-bit application software at 70 to 90 percent the speed of the regular Intel386 DX CPU.<ref name="Intel Corporation 1992, page 11"/>

The original 80386 was subsequently renamed i386DX to avoid confusion. However, Intel subsequently used the "DX" suffix to refer to the [[floating-point]] capability of the i486DX. The 387SX was an 80387 part that was compatible with the 386SX (i.e. with a 16-bit databus). The 386SX was packaged in a surface-mount [[Quad flat package|QFP]] and sometimes offered in a socket to allow for an upgrade.

The 16&nbsp;MHz 386SX contains the 100-lead BQFP. It was available for USD $165 in quantities of 1000. It has the performance of 2.5 to 3 MIPS as well.<ref name="Lewnes, Ann 1988, page 2"/> The low-power version was available on April 10, 1989. This version that uses 20 to 30 percent less power and has higher operating temperature up to 100&nbsp;°C than the regular version.<ref name="Lewnes, Ann 1989, page 2"/>

<gallery>
File:Intel386sx a 50 Kc.jpg|80386SX 16&nbsp;MHz
File:i386SX.jpg|A surface-mount version of Intel 80386SX processor in a [[Compaq]] Deskpro computer. It is non-upgradable unless hot-air circuit-board rework is performed
File:Intel 80386 SX die.JPG|[[Die (integrated circuit)|Die]] of Intel 80386SX
</gallery>