Sun open source chip design

Sun have released their new UltraSPARC T2 under the GPL. The chip, the latest in the SPARC line in the RISC family has eight cores, each with two arithmetic units, a floating point unit and an encryption engine. The cores share a pair of Ethernet ports and a PCI Express port. Direct speed comparisons of RISC chips and CISC (i.e. PC) chips is complicated by the fact that their internal units of processing are of different, giving them very different performance characteristics, but this chip appears to be aimed squarely at complex secure Java webservices.

The UltraSPARC T2 is not the first open source SPARC design, according to Wikipedia:

Two fully open source implementations of the SPARC architecture exist.

  • LEON is a 32-bit, single-thread SPARC Version 8 implementation, designed with a view to space applications. Source code is written in VHDL, and licensed under the GPL.
  • OpenSPARC T1 is a 64-bit, 32-thread implementation conforming to the UltraSPARC Architecture 2005 and to SPARC Version 9. Source code is written in Verilog, and licensed under many licenses. Most OpenSPARC T1 source code is licensed under the GPL. Source based on extant open source projects will continue to be licensed under their current licenses. Binary programs are licensed under a binary Software License Agreement.

RISC (Reduced Instruction Set Computer) chip design is funded on the observation that most of the instructions in traditional (or (CISC) Complex Instruction Set Computer) computers are executed very rarely. By reducing the number of instructions (and mapping the rarely-used instructions to a sequence of more commonly used instructions) the remaining instructions can be run faster. RISC chips tend to be smaller, lower power and easier to design than CISC chips. RISC chips are almost always faster than CISC chips at simple operations. CISC chips are almost always faster than RISC at the specific complex operations. How often which operations occur in day-to-day use is an open question. The SPARC line is specifically designed to optimise function (A.K.A. method) calls, which are increasingly common as modern software engineering increases the level of abstraction in programs.

By licensing the chip designs under open source licences, Sun getting advantages in a number ways:

  • They are clear and unambiguous foundation to it’s relationship with Fujitsu, the computer maker who has used SPARC chips to build several computers in the current top 500 supercomputers.
  • They make the chip designs available with minimum fuss to many academic institutions for teaching and research. That maintains a flow of both innovative ideas and fresh graduates both oriented to the SPARC platform. The relative simplicity of SPARC also adds to it’s appeal as a pedagogical tool.
  • By separating their hardware sales, hardware design and operating system businesses, Sun are creating an ecosystem in much the same way that IBM did when they opened up the PC. By growing this ecosystem they undermine the dominant ecosystem based around x68 and Microsoft Windows.
  • Their Java and systems integration businesses undoubtedly benefit from having a viable alternative to the dominant ecosystem.

Without a doubt, the open source community benefits from the existing of the SPARC ships. Both NetBSD and Linux run on a variety of SPARC chips, and indeed there is a project under way to port the whole Debian system to SPARC. The open sourcing of the chip designs gives kernel, compiler and linker hackers better access and tools to write faster, better, more robust code.