[4] To respond to this new situation, Intel wanted to provide a lower cost i486 CPU for system integrators, but without sacrificing the better profit margins of a full i486.
Intel were able to accomplish this with the i486SX, the first revisions of which were practically identical to the i486 but with its floating-point unit internally wired to be disabled.
[1]: 116–117 [5]: 162–164 [a] The i486SX was introduced in mid-1991 at 20 MHz, one core with 8kb of cache in a pin grid array (PGA) package.
[7] Later versions of the i486SX, from 1992 onward, had the FPU entirely removed for cost-cutting reasons and comes in surface-mount packages as well.
[1]: 117 The first computer system to ship with an i486SX on its motherboard from the factory was Advanced Logic Research's Business VEISA 486/20SX in April 1991.