The AMD K6-III microprocessor, the most powerful chip in the 6th-generation lineup, featured a cache design that included a full-speed 64-kilobyte level 1 (L1) cache, an internal full-speed backside 256-kilobyte level 2 (L2) cache, and a 100-megahertz frontside bus to an optional external level 3 (L3) cache. The combined total of 320 kilobytes of internal cache memory exceeded any of the x86-series chips of the period and dramatically increased computational speed of this advanced microprocessor.