Basic System Information

Last modified: Monday September 01, 2014 12:58 PM

Eos is a 3168-core IBM (iDataPlex) Linux cluster comprised of two different types of nodes: 324 are equiped with Nehalem and 48 with Westmere processors, both Intel products. Both implement 64-bit architectures and operate at 2.8GHz. The Nehalem is the quad-core X5550 processor, while the Westmere is the 6-core X5660. The Nehalem-based nodes are 2-socket 8-core SMP systems. Those equipped with Westmeres are 2-socket 12-core SMP's. Eos currently has 372 (324+48) nodes, all interconnected by a high-speed 4X Quad-Data Rate (QDR) Infiniband (IB) fabric. An IB link in the fabric supports full-duplex communication with bandwidth of 4GB/s in each direction. The interconnecting switch in this communication infrastructure is the Voltaire Grid Director 4700.

The 324 Nehalem nodes have the following roles: 314 are strictly compute nodes and accessible only by batch jobs; 5 are login nodes for cluster access and interactive processing; 4 are dedicated to I/O; and 1 is reserved for cluster services. All 48 Westmere nodes are for computation only and accessible in batch mode. However, four of them are equipped with graphics processors (GPUs).

Each node is a 64-bit shared-memory multi-processor system. The total memory per compute or I/O node is 24GB; four interactive/login nodes have 48GB each, the 5th one has 128GB. All cluster nodes run a 64-bit version of the RedHat or CentOS variants of the Linux operating system.

Bulk and global disc storage is provided by a 500TB DataDirect Networks (DDN) raid array, the S2A9900. All compute and login nodes access this storage via the 4 I/O nodes that are directly attached to the S2A9900.

Each node is equipped with a 146 giga-byte SAS disk drive. It's space is used mostly by the Operating System. Through the /tmp directory, a very limited amount of space can be used by user processes.

Eos graphic picture

Login Nodes

The hostname can be used for accessing the Eos cluster. This hostname will randomly direct you to one of the login nodes. The hostnames for the login nodes are, ..., You may also access a specific login node via its hostname.