System Units
Computing resources at ac3 are measured in terms of service units (SUs). 1 SU corresponds to 1 CPU core hour computing on Mclaren (SGI Altix shared memory machine, 256 cores) and Barossa (IA32 based Dell Linux Cluster, 304 cores). In each merit allocation round (every 6 month), about 1 million SUs are available on McClaren and 1.3 million SUs on Barossa. Resource charging on Mclaren will be modified by the amount of memory used by your program, via the following formula:
U= W * max [n, m/4]
where U is the usage charge, W the wallclock time used, n the number of CPUs allocated, and m memory allocated (expressed in GigaBytes). If you are using more than 4GB worth of memory in a single processor application, you should consider parallelising your application to reduce your wall clock time.
Please express your storage requirements using GigaBytes.
In the last box, please check the box if your program requires more than 512MB of RAM, and or whether it has code that is dominated by vector operations. Also select what method you use for parallelising your application (if any) as follows:
- none
- Not parallel at all
- script
- Job broken into small sequentially executed parts that
are backgrounded from the job script, or are submitted individually
to the batch queue.
- SMP
- Requires the use of a shared memory computer -- eg an
OpenMP coded program, or most commercial software that support
parallelism.
- HPF
- If you use a Data Parallel programming language, like
HPF or HPC++.
- MPI
- If you use a message passing environment like MPI or PVM.