The Iridis Compute Cluster

The current Iridis 4 is our fourth generation cluster and  is one of the largest computational facilities in the UK. In November 2013 Iridis 4 was ranked 179th in the world in the TOP500 list. Iridis provides High Performance Computing facilities in a professionally managed service environment and is available to the University's entire research community.

Access to IRIDIS

Iridis is primarily designed as a batch service for users who need to run either distributed memory parallel jobs, or multiple resource-intensive sequential jobs. If you are a researcher or postgraduate student and think that you have a good case for using Iridis, please fill in the online application form.  

IRIDIS Status and documentation

The main source of information on the Iridis 4 service is User Support wiki accessible to registered users. As well as documentation on how to access and use the service, it has information on training courses, background information on the facility, user forums and links to sources of further information. System Status page reports current status of the system, scheduled system maintenance and any ongoing problems/accidents.

IRIDIS 4 Components

  • 750 compute nodes with dual 2.6 GHz Intel Sandybridge processors;
  • Each compute node has 16 CPUs per node with 64 GB of memory;
  • 4 high-memory nodes with two 32 cores and 256 GB of RAM;
  • 24 Intel Xeon Phi Accelerators;
  • 3 login nodes with 16 cores and 125 GB of memory;
  • In total 12320 processor-cores providing 250 TFlops peak;
  • 1.04 PB of raw storage with Parallel File System;
  • InfiniBand network for interprocess communication;
  • Moab HPC Suite - advanced workload management system from Adaptive Computing;


Iridis 3 is a previous generation of Iridis launched in 2010, when it was ranked 74th in the world in the TOP500 list. In 2012 Iridis 3 underwent major upgrade, as a result number of processor-cores in Iridis 3 was increased by nearly 50%. Iridis 3 is currently used by SES Consortium and as a member of consortium University has access to a share of resources. Documentation and forums are hosted on Iridis3 wiki accessible to registered users.

Acknowledging the use of IRIDIS

When preparing a publication describing work that involved usage of Iridis, please ensure that you reference the Iridis cluster. Such recognition is important for acquiring funding for the next generation hardware, support services, data storage and infrastructure. The following text is suggested as a starting point. Please, feel free to augment or modify as you see fit.

''The authors acknowledge the use of the IRIDIS High Performance Computing Facility, and associated support services at the University of Southampton, in the completion of this work.''

In addition, we kindly ask you to notify us of any report, conference papers, journal article, theses which contain results which were obtained on Iridis by sending an email to