Cyrix M II-300GP, 66 MHz Bus, Dark

After Cyrix was purchased by National Semiconductor in 1997 they terminated their foundry agreement with IBM. National fabricated their own chips and the 6x86MX was re-named MII. Compared to early 6x86MX CPUs the MII had some enhancements to its processor core. Heat output was reduced allowing it to rise to clock speeds over 220MHz. The MII also required non-standard bus speeds at 75 or 83MHz on socket 7 boards and therefore had some troubles with stability.