All the top server CPU vendors--Advanced Micro Devices, IBM, Intel, Fujitsu and Sun Microsystems--will present on their latest or next-generation chips. Competition is expected to be intense between Intel's Nehalem EX, AMD's Magny Cours, IBM's Power7 and Sun's Rainbow Falls.

However, Sun did not submit a paper on Rock, its high-end server CPU first described in February 2008, leading to speculation the company may have canceled the chip. Sun lost Rock's chief architect, Marc Tremblay, to Microsoft earlier this year and the merger with Oracle cast uncertainty over Sun's future Sparc efforts.

Rock provided hardware support for two advances in parallel processing, transactional memory that would eliminate today's inefficient data locking techniques and scout threads that could pre-fetch data to cache in anticipation of program branches. "The signs are not looking good, so we may be writing an epitaph for Rock soon," said Nathan Brookwood, principal of market watcher Insight64 (Saratoga, Calif.).

Fujitsu may help Sun fill a hole if it cancel's Rock. The company will describe an eight-core Sparc processor at Hot Chips, and Fujitsu and Sun have a long established relationship of selling each other's systems.

Also missing from the Hot Chips program is Intel's Tukwilla, the first Itanium CPU to use Intel's Quick Path Interconnect and an on-board memory controller. Intel deferred the Tukwilla launch from this fall to early next year.

"My reading on that was they probably found some places where it was not scaling as good as they thought it should," said Brookwood.

Nvidia founder and chief executive Jen-Hsun Huang will give a visionary keynote at Hot Chips. However there are no graphics processor papers on the program.

The next-generation graphics chips are expected to launch following the release this fall of Microsoft's Windows 7 and its DirectX 11.0 application programming interface. It supports a new DirectX Compute ability to manage multiple cores on graphics and host processors, handling similar jobs as the OpenCL software supported by Apple and Nvidia's CUDA parallel programming environment.