MX2 Processor Module: Twice the Processors in Half the Volume

Abstract

Computer manufacturer’s are constantly trying to tweek more performance out of their existing products by using the highest performing processors. Typically, manufacturers upgrade the platforms by simply replacing the old processor with the latest speed processor. Like other manufacturers, HP generally follows this practice with the exception ot HP’s innovative mx2 module. This unique module used two Itanium-2 “Madison” processors packaged in the same physical volume as a single Itanium-2 processor. In addition, the module plugs into a standard Itanium-2 motherboard socket and requires no additional power capacity. As a result, the development team was able get 50% more performance [1] from a socket without increasing power by actively managing the power to the two processors. Thus, the performance per watt was substantially improved. This paper will provide an overview of some of the key packaging and power innovations that made the processor module a reality such as: 1) mezzanine power for space savings. The standard Itanium 2 processor has a power converter adjacent to the processor. HP engineers chose to put power on top of the processor which provided more room but made cooling the processors a challenge. 2) high performance mechnical gap filler. One of the biggest issues in the module was to develop a thermal gap filler that absorbed 0.060” of tolerance between the two processors. The thermal resistance of this technology was an order of magnitude better than anything commercially available in the industry. 3) Power Aware Architecture. This newly developed power mangement technology actively controls power to the processors. When system (thermal and power) extremes were exceeded by worst case abnormal code, the performance was throttled down until the worst case scenario had past. The combination of these advancements has delivered an innovative solution for a highly challenging design problem. This module is now shipping as the mx2 processor module in HP’s Integrity Servers and has been viewed as an engineering marvel by HP executives.