Sun4d is a computer architecture introduced by Sun Microsystems in 1992. It is a development of the earlier Sun-4 architecture, using the XDBus system bus, SuperSPARC processors, and SBus I/O cards. The XDBus was the result of a collaboration between Sun and Xerox; its name comes from an earlier Xerox project, the Xerox Dragon. These were Sun's largest machines to date, and their first attempt at making a mainframe-class server.

The SPARCstation 20 or SS20 is a discontinued Sun Microsystems workstation introduced in March 1994 based on the SuperSPARC or hyperSPARC CPU. It is one of the last models in the SPARCstation family of Sun "pizza box" computers, which was superseded by the UltraSPARC design in 1995.