8048x > IntelA80487SX
Modified: April 23, 2005, 4:37 pm
Manufacturer:Intel
Model:A80487SX
Speed:33MHz Max
Type:80487
Data Code:9134
Introduced:1989
Transistors:1.2 million
Package:168CPGA
Process:1 Micron
Architecture:80 bit FPU
Used in:80486SX Systems
Description:The successor to the 80386 processor, Intel 80486
(i486) added new important features:

Floating Point Unit was integrated with the
processor

Internal clock doubling and tripling allowed the
processor to run much faster in existing
motherboards.

Power management features and SMM (System
Management Mode) became a standard feature of the
processor.

Instruction set optimization resulted in even
greater performance of the processor. Different
versions of the 80486 were produced, two most
common versions are 80486DX with integrated FPU,
and 80486SX without FPU. The Intel 80486 was
produced at speeds up to 100 MHz. AMD produced
even faster 120 and 133 MHz versions of the 80486.

Early SX chips had the FPU disabled, later ones
had it removed from the die completely, saving
400,000 transistors.

DX/SX = 1x Multyplier (8k Cache)
DX2/SX2 = 2 x Multyplier (8k Cache)
DX4 = 3x Multiplier (16K Cache)

Bus Speed: 33MHz
This is the Intel FPU for the SX systems.
In reality it is a DX CPU that just takes over
from the old SX chip.