The Pentium III 600 was the last processor of the Katmai 0.25 µm line. Released on late July 1999 to compete with the newly-announced Athlon from AMD, The 600 Mhz Katmai wasn't really produced in mass quantity. This Sample were produced the same week as the official launch : This is a proof for an early announce than expected. Based on the kC0 core and featuring 512 KB of off-die L2 cache clocked at half the rated speed (300 Mhz), this CPU was outperformed by the 600 Mhz Coppermine core.