Gigabit/s Network Interfaces for Parallel and Distributed Systems

Prof. Thomas M. Stricker
joint work with Christian Kurmann
Institut für Computersysteme, ETH Zürich

The architects of parallel and distributed systems like PC clusters can choose among approximately half a dozen fairly established Gigabit/s interconnect technologies. Most of them are shipped as a add-on cards that plug directly into the PCI bus of the PC motherboards used as nodes in such systems.

In this talk I am presenting two recent research contributions in the area of Gigabit Networking: First I will discuss a model that serves as a common ground to compare the different interconnect architectures in several different settings between coarse grain and fine grain communication. I will take a closer look at the architecture and the
performance characteristics of the two examples: Myrinet and Dolphin SCI and compare them to the interconnect of a Cray T3D, an old but very fast MPP. Second I will introduce "speculative defragmentation", a highly sophisticated software architecture to speed up GigabitEthernet network processing on machines that are slower than the network requiring a true zero copy protocol architecture in order to deliver a reasonable fraction of a Gigabit in throughput.

The software tricks around speculative fragmentation will lead to a critical review of Ethernet as a high speed interconnect and permit a conclusion with a outlook to future interconnects like Infiniband.

Projects: www.cs.inf.ethz.ch/CoPs 
Slides: www.cs.inf.ethz.ch/CoPs/speedup