The original Klamath Pentium II microprocessor (Intel product code 80522) ran at 233, 266, and 300 MHz and were produced in a 0.35 µm process.[3][6] The 300 MHz version however only became available in quantities later in 1997.[6] These CPUs had a 66 MHz front side bus and were initially used on motherboards equipped with the aging Intel 440FX Natoma chipset designed for the Pentium Pro.[7]
In Intel's "Family/Model/Stepping" scheme, Klamath CPUs are family 6, model 3.