Electro-Photonic NoC Designs for Kilocore Systems
Electro-Photonic NoC Designs for Kilocore Systems
复制标题
千核系统的电光子 NoC 设计
DOI：
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发表时间：
2016
影响因子：
2.2
通讯作者：
A. Joshi
中科院分区：
文献类型：
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作者：
José L. Abellán;Chao Chen;A. Joshi
多核系统中不断增加的核数需要相应的大的片上网络（NoC）带宽来支持覆盖的应用。然而，使用电链路技术以节能的方式提供这种大带宽是不可能的。为了克服这个问题，光子链路技术被提出作为替代。这项工作探讨了使用光子链路设计未来千核系统的NoC架构的限制和机会。本文探讨了三种不同的NoC设计：ElecNoC，一种电集中的二维（2D）网格NoC；HybNoC，具有光子多横条NoC的电集中二维网格；PhotoNoC，光子多总线NoC。我们考虑了私有和共享缓存架构，为了利用光子链路的大带宽密度，我们研究了预取和主动非阻塞缓存的使用。我们使用当代大数据工作负载的分析表明，具有共享LLC的非阻塞缓存可以最好地利用Kilocore系统中光子链路的大带宽。此外，与基于elecoc和hybnoc的Kilocore系统相比，基于photonoc的Kilocore系统的性能分别提高了2.5倍和1.5倍，并且可以分别支持高达2.1倍和1.1倍的带宽，而整个系统的功耗相当。
The increasing core count in manycore systems requires a corresponding large Network-on-chip (NoC) bandwidth to support the overlying applications. However, it is not possible to provide this large bandwidth in an energy-efficient manner using electrical link technology. To overcome this issue, photonic link technology has been proposed as a replacement. This work explores the limits and opportunities for using photonic links to design the NoC architecture for a future Kilocore system. Three different NoC designs are explored: ElecNoC, an electrical concentrated two-dimensional- (2D) mesh NoC; HybNoC, an electrical concentrated 2D mesh with a photonic multi-crossbar NoC; and PhotoNoC, a photonic multi-bus NoC. We consider both private and shared cache architectures and, to leverage the large bandwidth density of photonic links, we investigate the use of prefetching and aggressive non-blocking caches. Our analysis using contemporary Big Data workloads shows that the non-blocking caches with a shared LLC can best leverage the large bandwidth of the photonic links in the Kilocore system. Moreover, compared to ElecNoC-based and HybNoC-based Kilocore systems, a PhotoNoC-based Kilocore system achieves up to 2.5× and 1.5× better performance, respectively, and can support up to 2.1× and 1.1× higher bandwidth, respectively, while dissipating comparable power in the overall system.