KCM (Knowledge Crunching Machine) is a high-performance back-end processor which, coupled to a UNIX* desk-top workstation, provides a powerful and user-friendly Prolog environment catering for both development and execution of significant Prolog applications. This paper gives a general overview of the architecture of KCM stressing some new features like a 64-bit tagged architecture, shallow backtracking and an original memory management unit. Some early benchmark results obtained on prototype machines are presented. They show that KCM, which runs at a peak speed of 833 Klips on list concatenation, compares favorably with other dedicated Prolog machines and available commercial systems running on fast general purpose processors.