4 denotes a sun- 1987 series produced by Sun Microsystems of Unix workstations and servers. The original Sun -4 series was like the Sun -3 series of VMEbus systems, but - were equipped with their own on Sun's SPARC V7 RISC architecture based microprocessors - instead of 68k processors. The Sun -4 architecture is supported by SunOS from version 3.2.

In 1990, the Sun -4 series in favor of the SPARCstation and server series has been discontinued. However, some of the early SPARCstation and server models has been to 1991, Sun -4 model names.

The term sun -4 has also been used to describe the basic architecture of a SPARC -based system in computer development.


The models of the Sun -4 series are listed here in approximate chronological order.

Sun 4/110, 4/150, 4/ 260 and 4/280 systems, which have been upgraded with the Sun 4300 CPU board were accordingly called Sun 4/310, 4/350, 4/ 360 and 4/380.


  • Sun - 4c: This variant has instead of a VMEbus system via a 32 -bit SBus system and introduced a new MMU architecture. The SPARCstation 1 was the first Sun - 4c model.
  • Sun - 4e: This variant combines the VME system with the Sun - 4c architecture. It was in the embedded SPARCEngine 1 (Sun 4 / E) used VME controllers. The Sun -4e architecture was originally developed by Force Computers and licensed from Sun.
  • Sun - 4m: Originally a rating based on the MBus system multiprocessor variant, which was introduced to the Sparc server 600MP series. They also referred to single-processor systems with SPARC V8 architecture such as the SPARCstation 5
  • Sun 4d An expandable to up to 20 processors, multiprocessor variant, based on the XDBus system. It was used in the Sparc Server 1000 and Sparc Center 2000 series.
  • Sun -4u: This variation introduced the 64- bit UltraSPARC (SPARC V9 ) processor architecture and the UPA - processor interconnect. It was first used in the Sun Ultra series.
  • Sun 4U1: This variant refers to the 64- core multi- processor architecture in the Enterprise 10000 ( Starfire ) system.
  • Sun - 4v: This variant is based on the Sun -4u architecture and expanded them to hypervisor virtualization. It was first used in the UltraSPARC T1 system.