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Stokes Supercomputer


Stokes (stokes.ichec.ie is an SGI Altix ICE 8200EX cluster with 320 compute nodes. Each compute node has two Intel (Westmere) Xeon E5650 hex-core processors and 24GB of RAM. This results in a total of 3840 cores and 7680GB of RAM available for jobs.

The nodes are interconnected via two planes of ConnectX Infiniband (DDR) providing high bandwidth and low latency for both computational communications and storage access. Storage is provided via a Panasas ActiveStor 5200 cluster with 175TB (formatted) of capacity to the compute nodes via a PanFS filesystem.

In addition to the compute nodes a set of service and administrative nodes provide user login, batch scheduling, management, etc.


A large number of scientific software packages, libraries, compilers and other tools are installed and maintained on Stokes by ICHEC. A full listing of these is available on the software page.

Scheduling Policy

The following queues are available on Stokes:

  Job Size (cores) Maximum Walltime Maximum Available Cores
DevQ 12 - 96 30 minutes 192
ShortQ 24 - 516 24 hours 3264
ProdQ 24 - 516 84 hours 3264
LongQ 12 168 hours 192


  • Users should avoid specifying a queue in their PBS scripts. Specifying the walltime and processor requirements will result in the job being routed to the optimum queue.
  • Processing cores on Stokes are allocated in multiples of twelve (one node). This means that users can only request core counts of 12, 24, 36, 48...
  • Hard and soft throttling limits are in place to prevent a single user from flooding the entire system.
  • Queued jobs gain priority at different rates depending on many factors.


Introductory documentation for Stokes is provided in our documentation section.


Some photos of the Stokes system:


Stokes was funded under the PRTLI Cycle 4 funded project e-INIS. Direct contributions were received to Stokes from six institutions: UCD, NUIM, DCU, NUIG, UL and DIAS and each owns a percentage of system time.