Sun is working on new "Rock" parallel processing standard

At the start of the International Solid-State Circuits Conference (ISSCC) on Monday, Sun Microsystems intends to present the first details of its 16-core SPARC processor, code-named "Rock". With two simultaneous software threads per core, the server chip can simultaneously process 32 requests as well as 32 scout threads. Sun uses an in-order architecture which, due to its higher number of parallel processes, will scale linearly with the number of threads, despite the fact that it is slower than Intel's x86 architecture. The simpler architecture saves chip space and energy so that a considerably larger number of cores can be placed on the 396 square millimetre die, explained Sun's chief designer Marc Tremblay.

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Instead of having private cache structures for every core, four processing cores share a common command cache (40 Kbytes), two data caches and two floating point arithmetic units. The processor uses a 65nm process with a clock speed of 2.3GHz. Among the server chip's most important new features is a hardware-based memory management mechanism called transactional memory. The mechanism groups and processes security-relevant instructions together. In contrast to other processors, main memory areas which are in use do not need to be available exclusively to every thread for read and write access. Therefore, considerably less effort is needed for synchronisation, and "deadlocks" where instructions exclude each other from memory access are less likely to occur. The first software implementations for transactional memory have already been developed and more research is going into increasing the efficiency of parallel programs. Sun is planning to implement the processor in hardware, which promises considerably better performance than a software solution.

The Californian company is promoting its chip in an attempt to gain the software industry's support. Database vendors play a particular key role; however, so far none of the relevant market vendors (IBM, Microsoft and Oracle) have agreed to support it. Sun plans to publish an API as well as simulation tools under open source licences to promote software development. This also casts a new light on Sun's recent take-over of database vendor MySQL: the company could gain a competitive edge by offering parallel database and server mechanisms.

(Erich Bonnert)

(ehe)