sentences:  Some of these are notable for supporting symmetric multiprocessing some time before Sun themselves produced multiprocessor systems.Even when Sun produced multiprocessor systems, SunOS uses an asymmetric multiprocessing model rather than OS/MP's symmetric multiprocessing model; Sun would not adopt symmetric multiprocessing until the release of Solaris 2.0 in 1992.Due to the cost of engineering and producing new systems to compete with Sun's increasingly competitive hardware offerings and the loss of symmetric multiprocessing as a distinguishing feature, in 1994, Solbourne left the computer hardware business, with Grumman Systems Support Corporation taking over support for Solbourne customers until 2000.