EAGER:Scaling On-Chip Interconnects for Exascale Systems

本研究旨在克服实现1000核（千核）处理器所需解决的极端挑战。具有数十个核心的处理器今天已经在商业产品中。千核处理器可以将我们带入片上服务器和片上超级计算机的时代。片上网络是处理器中两个节点之间进行通信的媒介，是千核处理器的骨干网络。不幸的是，当前的片上网络解决方案是不够的，因为它们在功率和性能方面都不能扩展到几十个核之外。为了实现1000多个内核的宏伟设计目标，并提供现实的功耗预算，互连技术需要至少提高15倍的能效，同时提供至少与当前相同的每内核吞吐量水平。本项目研究三个相互关联的解决方案，以渐进的方式应对上述挑战：（1）开发一种低功率和能量比例的互连架构，其采用大量较窄的网络，（2）使用高基数Swizzle-Switch作为用于互连多个网络的构建块，以及（3）重新设计具有多个网络和Swizzle-Switch的网络架构，使用3D集成与硅通孔，以实现超过1000个核心的可扩展性。该项目将展示千核处理器的可行性。如果能够制造出这样的处理器，它们可能会对未来的兆兆级系统产生巨大影响，例如云计算服务器和高性能计算系统，这些系统具有许多应用，包括药物发现、国防、信息分析和社交网络。

This research aims to overcome the extreme challenges that need to be solved to realize a 1000-core (kilocore) processor. Processors with tens of cores are already in commercial products today. A kilocore processor could take us into the era of Server-on-Chip and Supercomputer-on-Chip. On-chip network is the medium through which two nodes in a processor can communicate, and therefore constitutes the backbone of a kilocore processor. Unfortunately, current on-chip network solutions are inadequate as they do not scale in terms of both power and performance beyond a few tens of cores. To reach the ambitious design goal of 1000+ cores with realistic power budgets, the interconnect technology needs to be at least 15 times more power efficient while providing at least the same level of throughput-per-core as today. This project investigates three interrelated solutions to meet the above challenge in an evolutionary manner: (1) Developing a low-power and energy-proportional interconnect architecture that employs a larger number of narrower networks, (2) Using high-radix Swizzle-Switches as the building blocks for interconnecting the multiple networks, and (3) Re-designing network architecture with multiple networks and Swizzle-Switches using 3D integration with Through-Silicon-Vias to achieve scalability beyond 1000 cores. This project will demonstrate the feasibility of kilocore processors. If such processors can be built, they could have a tremendous impact on future exascale systems such as cloud computing servers and HPC systems that have many applications including drug discovery, defense, information analysis, and social networking.