KCM (KnowledgeCrunching Machine) is a highperformance back-end processor which, coupled to a UNIX' desk-top workstatrbn, provides a powerful and user-friendfy Prolog environment catering for both development and exewtbn of sbnificant Prolog applications. This paper gives a general ovem'ew of the architecture of KCM stressing some new features like a 64&t tagged architeoture, shallow backtracking and an original memory management unit. Some early benchmark results obtained on prototvpe machines are presented. They show that KCM, which runs at a peak speed of 833 Klips on fist concatenation, compares favorably with other dedicated Prolog machines and available commercial systems nmning on fast general purpose plOC8SSOrS.