My bet thet it was the ross-cypress (SM30 ??) probably THE slowest 4m around. It was the original dual cpu on the 600smp. It was so slow that even sun replaced them all. The ss2 had a 4c.and runs at 40mhz, I think the original ross-cypress was at 30-36mhz. The Ross-cypress might have used the 4c core with the mbus. yeah these cpus ran at 33mhz. ISTR that the 36mhz ones are sun4m... you seem to know what i'm talking about :-)