"Although its codename (C5X) seems to indicate a mere enhancement of the Cyrix III (C5A), the "Cyrix 4" is indeed a completely new design. The list of similarities between Cyrix III and "Cyrix 4" is quite short, with the amount of L1 cache (128K) and use of the P6 bus being primary among them. "
FULL STORY @ VIAHARDWARE (http://www.viahardware.com/c5x.shtm)
