Stokes Supercomputer
Hardware
Stokes (stokes.ichec.ie is an SGI Altix ICE 8200EX cluster with 320 compute nodes. Each compute node has two Intel (Harpertown) Xeon E5462 quad-core processors and 16GB of RAM. This results in a total of 2560 cores and 5120GB of RAM available for jobs.
The nodes are interconnected via two planes of ConnectX Infiniband (DDR) providing high bandwidth and low latency for both computional communications and storage access. Storage is provided via a Panasas ActiveStor 5200 cluster with 84TB (formatted) of capacity to the compute nodes via a PanFS filesystem.
In addtion to the compute nodes a set of service and administrative nodes provide user login, batch scheduling, management, etc.
Software
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 | 8 - 64 | 30 minutes | 128 |
| ShortQ | 32 - 256 | 24 hours | 2176 |
| ProdQ | 32- 256 | 84 hours | 2176 |
| LongQ | 8 - 16 | 168 hours | 128 | * LargeQ | 512 | 120 hours | 512 |
* The LargeQ is currently available to Class A projects only. It requires that sufficient jobs be queued up prior to resources being made available.
Note:
- 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 eight (one node). This means that users can only request core counts of 8, 16, 24, 32...
- 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.
Documentation
Introductory documentation for Stokes is provided in our documentation section.
Photos
Some photos of the Stokes system:
Acknowledgement
Stokes was funded under the PRTLI Cycle 4 funded project e-INIS. Direct contributions were received to Stokes from University College Dublin and National University of Ireland. Maynooth and each owns a percentage of system time.
