Myrinet
Myrinet , ANSI / VITA 26-1998, is a proprietary high-speed local area network system that was developed by the company Myricom to create the connection between different machines in a computer cluster . Myrinet has significantly less protocol control effort ( overhead ) than other standards such as Ethernet and thus enables higher data throughput, fewer interface cards and shorter latency times. Although it can also be used as a traditional network system, most of the time it is used directly by the applications, bypassing the operating system .
Myrinet physically consists of two fiber optic cables , transmit and receive lines, which are connected to the computer with a single connector. The individual computers are then connected to one another with the help of routers and switches . Myrinet includes a number of fault tolerance precautions, most of which are handled by the switches. These include flow control, error control and heartbeat monitoring on each individual connection. The first generation of the hardware offered 512 Mbit / s data transmission in both directions, later versions then supported 1.28 Gbit / s and 2 Gbit / s. The latest "fourth generation Myrinet" supports 10 Gbit / s and is compatible with 10 Gigabit Ethernet on the hardware level ( physical layer ) (cables, connectors, distances, signals) .
The data throughput of Myrinet is close to the theoretical maximum of the physical layer. An actual rate of 1.98 Gbit / s is achieved on the 2.0 Gbit / s adapters. The dual-rail cards with two bidirectional links have a data rate of 3.95 Gbit / s. The latency for cards with a 333 MHz RISC processor is 2.6 µs. The fourth generation offers a measured bandwidth of 9.8 Gbit / s. When using sockets, benchmarks such as netperf show a throughput of 9.7 Gbit / s. For computer clusters, the low latency is even more important than the high data throughput, since, according to Amdahl's law, the overall performance of a high-performance parallel system is determined by the slowest sequential process, which is usually the signal propagation time over the network.
Myrinet has been displaced more and more by Gigabit Ethernet and Infiniband in recent years . In November 2007, Myrinet only had a share of 3.6% in the TOP500 list of supercomputers.
Individual evidence
- ↑ Interconnect Family share for 11/2007 (top500.org) ( Memento of the original from April 21, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
Web links
- Myrinet Overview ( Memento from May 14, 2011 in the Internet Archive )