EAGER:Scaling On-Chip Interconnects for Exascale Systems

这项研究旨在克服实现1000核（千核）处理器所需要解决的极端挑战。如今，拥有数十个核心的处理器已经出现在商业产品中。千核处理器可以把我们带入服务器芯片和超级计算机芯片的时代。片上网络是处理器中两个节点进行通信的媒介，因此构成了千核处理器的骨干。不幸的是，目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内核以上。为了在实际的功耗预算下实现1000+核的宏伟设计目标，互连技术需要至少提高15倍的功耗效率，同时提供至少与目前相同的每核吞吐量水平。这个项目研究了三个相互关联的解决方案，以一种渐进的方式来应对上述挑战：(1)开发一种低功耗和能量比例的互连架构，采用更多的窄网络；(2)使用高基数Swizzle-Switches作为多个网络互连的构建块；(3)重新设计具有多个网络和Swizzle-Switches的网络架构，使用3D集成与through silicon - vias实现超过1000核的可扩展性。这个项目将展示千核处理器的可行性。如果这样的处理器能够建成，它们可能会对未来的百亿亿级系统产生巨大影响，比如云计算服务器和高性能计算系统，这些系统有许多应用，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.