IBM's POWER and POWER2 were also many (8-10 depending) chips in CMOS which was an exotic approach as most RISCs had converged to single die microprocessors but

IBM's POWER and POWER2 were also many (8-10 depending) chips in CMOS which was an exotic approach as most RISCs had converged to single die microprocessors but made it possible to beat a lot of vendors in the superscalar punch and push the complexity of SMP out a while (for both vendor and user). The POWER2SC converged it all onto one die, and then eventually IBM became well known for exotic RISC MCMs. In the mainframes the TCM is somewhat famous, really beautiful Bipolar designs with relatively low gate count but a ton of high performing dice (and high heat, hence TCM) on an exotic MCM.