September 1999

Alpha Processor, Inc. (API), debuting the fastest processor in the world running at room temperature - the 1GHz Alpha 21264 processor - utilizes Flotherm thermal management software from Flomerics to analyse the cooling requirements of its record-breaking processor, which runs at nearly twice the speed of today's fastest Intel Xeon solution.

The new processor operates at room temperature without the aid of refrigerants, cooling pipes, etc., and is due for release in August 2000. The 21264 processor is housed within API's Alpha Slot B packaging that dissipates a 100W of power, together with a PCB, and is cooled by three forced airflow axial fans. API's Alpha Slot B significantly lowers production costs and inventory requirements, offering industry standard packaging technology for the world's fastest processor.

Recognising that expert thermal design is the key to getting today's processors to run faster, API worked with Flomerics' Thermal Design Services Team to reduce the thermal resistance of the heat sink. A reduction in thermal resistance from 0.4 to 0.3 °C/W results in the processor itself running 10 degrees cooler. The first Flotherm thermal analysis, used to determine the air flow and heat dissipated by the module, revealed that the fin pitch of the existing heat sink was already near to optimal, but that the heat spreading rate within the base of the heat sink was a limiting factor. Keen to further reduce the operating temperature of the processor, the engineers at API and Flomerics collaborated to find inexpensive solutions, one being a recommendation that copper be inserted into the base of the extruded aluminium heat sink. This offered a more cost-effective solution than manufacturing a heat sink with many very thin fins. The thermal performance of the heat sink has thus been boosted significantly and its operating life maximised.

A total of 6 Flotherm simulations were run, with the entire re-design process taking just 1 month, including several iterations between API's Project Manager and Flomerics' Thermal Design Team.

Commenting on the project, Mike Beale, Electro Mechanical Design Engineer, API, said "Flomerics' expertise in heat sink design offered a robust solution enabling us to continue expanding the boundaries of microprocessor technology. As existing users of Flotherm we knew that the numerical results would give us faster and more complete design information than could be obtained from numerous physical prototypes built in the laboratory. Allowing us to by-pass the prototyping stage, the Flotherm predictions correlated almost exactly with the experimental results."

Concluding, Dr. Mike Reynell, Director of Marketing, Flomerics, commented, "Thermal analysis has become an integral and crucial part of the package design process for modern chip packages and is the key to getting chips to run faster and more reliably. Anyone wishing to create a competitive chip package must consider thermal management issues at a very early stage in the design, as API has done. Flotherm's simple, intuitive user interface, backed up by Flomerics' ten years experience in thermal analysis makes the package ideal for this purpose."