The IBM 5x86C is an IBM-branded and -produced version of the Cyrix-designed Cyrix Cx5x86 CPU.
Previous IBM x86 processors, IBM 386SLC and IBM 486SLC, were based on modified Intel designs.
75 MHz capable edition for 25 MHz (25x3) front side bus
100 MHz capable edition for 33 MHz (33x3) front side bus