The evolution of datacenters and the drive towards exascale high-performance computing is creating a long term platform trend towards increased node density. Multiple CPU (Central Processing Unit) nodes will need to be housed in a common board, card or even package substrate. In order to achieve platform cost, density and power efficiency, more of the platform capabilities need to be absorbed into fewer components. Present day computing architecture requires a dedicated Platform Controller Hub (PCH) per CPU node, necessitating multiple instances of the PCH on a shared board having multiple CPUs or CPU complexes.
Scaling existing platform architectures to dense form factors forces unnecessary duplication of large numbers of functions in each compute node and creates new problems that are unique to dense form factor platforms. The high density value proposition of future system solutions gets compromised by the requirement of a dedicated PCH per node. Elimination of the PCH through monolithic integration of the PCH functionality into CPU die is not power/area efficient, and does not provides a scalable solution either. Thus, there is a need for an improved platform architecture that will reduce or eliminate redundancy on the platform and meet the requirements of dense platform.
One approach to increasing form factor density is to employ multi-node aware platform controller hubs (MN-PCH). Under this scheme, a single MN-PCH is configured to replace the functionality provided by multiple PCHs under conventional multi-node shared board architectures. Longer term data indicates value of mission critical based computing moving from the traditional 8 socket glueless or 4 socket servers to a 2 socket higher RAS (reliability, availability, and serviceability) system. This does not diminish the 5-9's reliability standards, but requires that the newer system architectures must not be subject to a failure of the chipset interconnect. To accomplish this higher reliability system, the system architectures need to ensure that chipset components when coupled with the MN-PCH support this usage.