CEMAG computer, architecture

Description

The computer is made of five SGI Altix 450 machines, interconnected with two Infiniband networks, IB0 and IB1.

• A frontal machine, jxb, with two Intel® Itanium Montecito dual core processors, giving 4 CPU, ensure cluster control, users logins, network services.

  This machine also controls a disks enclosure of 10 Tb, connected via a double Fiber Channel link FC0 and FC1, and makes available the storage space via NFS.

• Four computation dedicated machines, jxb01 à jxb04, feature each 34 Itanium dual core processors, giving 68 CPU with 64 available to users tasks. The «computing available» total is 256 CPU.

Connections

• In each computing node, processors are interconnected via Numalink (red links on the figure).

• An Infiniband network IB0, installed with a IPoIB layer, is partialy used (almost 25%) for network services, NIS, NFS, PBS, etc.

• The remainding IB0 bandwidth and the second Infiniband network IB1 are dedicated to MPI communications.

• The frontal machine jxb is also connected on the Ethernet network of the Physics Department. It is the only possible access to the cluster from users workstations.

  This machine has two names, jxb on the laboratory network and jxb00 on the internal cluster.