The main 'communications' rack of Iridis (in the orginal Iridis installation). Showing (top) the Extreme Alpine Ethernet switch (with 100Mbit links to the orginal nodes and Gigabit links to the internet, backup server, IO nodes and to a 2nd Alpine switch in the May 2002 extension racks). Below is the Myrinet 2000 switch with 80 copper ports (black cables) and 40 fibre ports (orange cables). The Myrinet switch provides low latency (<10usecs) and high bandwidth (between 140 and 250Mbytes/sec depending upon node type) connections between 115 nodes).