Intel® QuickPath Interconnect Architectural Features Supporting Scalable System Architectures

Single processor performance has exhibited substantial growth over the last three decades [1] as shown in Figure 1. What is also desired are techniques which enable connecting together multiple processors in order to create scalable, modular and resilient multiprocessor systems. Beginning with the production of the Intel® Xeon® processor 5500 series, (previously codenamed “Nehalem-EP”), the Intel® Xeon® processor 7500 series (previously codenamed “Nehalem-EX”), and the Intel® Itanium™ processor 9300 series (previously codenamed “Tukwila-MC”), Intel Corporation has introduced a series of multi-core processors that can be easily interconnected to create server systems scaling from 2 to 8 sockets. In addition, OEM platforms are currently available that extend this up to 256-socket server designs1. This scalable system architecture is built upon the foundation of the Intel® QuickPath Interconnect (Intel QPI). These Intel micro-architectures provide multiple high-speed (currently up to 25.6 GB/s), point-to-point connections between processors, I/O hubs and third party node controllers. The interconnect features, as well as the capabilities built into the processor's system interconnect logic (also known as “uncore”), work together to deliver the performance, scalability, and reliability demanded in larger scale systems.