Scientific Computing Seminar

Myrinet NICs are built around a programmable RISC processor that operates directly in the data path. This architecture yields flexibility and extendability, at a cost of software processing. However, current low-level communication interfaces such as GM fail to fully leverage this programmability and offer limited services and performance. Myrinet eXpress (MX), a new communication layer, was specifically designed to harness this capability in order to improve the performance of common software interfaces such as MPI and Ethernet emulation.

MX embeds functionalities into the network to assist and improve the communication protocols on the host, while providing a very short critical path. MX purposefully runs part of the host protocol closest to the data path, thereby decoupling the progression of the protocol from the execution of the host application. The results show impressive low-level point to point performance but also a sharp improvement of higher level metrics such as overlapping of communication and computation for MPI and high throughput and low overhead for IP.