(L1 cache, level one cache) A Small, faSt cache memory inSide or cloSe to the CPU chip. For example, an Intel 80486 haS an eight-kilobyte on-chip cache, and moSt PentiumS have a 16-KB on-chip level one cache that conSiStS of an 8-KB inStruction cache and an 8-KB data cache. The larger, Slower Secondary cache iS normally connected to the CPU via itS external buS. (1997-06-25)