Applying for External Computing Time

Differences between Tiers

• At the lowest level, projects are granted quickly (a few days to a few weeks at most)  based on a short description of the project and the intended outcome. In general, no stringent restrictions are placed on the application codes at this level.

• At the most competitive levels, applications are peer-reviewed both scientifically and technically. The time betwen application and project start can be up to half a year and the technical review requires scalability and efficiency to be demonstrated for the employed algorithms and codes. When projects end, computing centers ask principal investigators (PIs) for lists of publications and the submission of projects reports. Of the latter, it may be that both a technical report as well as a project summary suitable for the general public (to be published on the centre website) may be requested.

• At the intermediate level, the selection criteria are naturally less stringent and the time between application and project start is generally between a few weeks to a few months.

• While not always true, calls at the most selective tiers are regular (twice to four times a year) while calls at the lower tiers are rolling or continuous and may be reviewed quite quickly. Some rolling calls have regular cut-offs, however (applications can be submitted at any time but are only reviewed n times a year).

Overarching Organisations

At Tier-3, HPC.NRW acts as a bridge and coordinator between Tier-3 and Tier-2 centres in NRW, providing support, documentation, training and fostering a cooperative atmosphere within the state.

At Tier 2, computing time is avaiable in Aachen, Cologne and Paderborn for researchers at public research institutions in the state of NRW. Nationally, the  NHR Initiative is currently in the process of reorganising access to these resources, such that researchers from any state can apply for access to resources in any other state. NHR should lead to a more unified application procedure at this level while at the same time improving the available support in particular research fields.

At Tier-1, the Gauss Center for Supercomputing (GCS) coordinates between the top computing centers in Germany, providing a unified application procedure as well as advanced training and support activities. It also acts as a bridge between Tier-2 and Tier-1.

Beyond Germany, PRACE and EuroHPC both offer rolling and regular calls at different levels. On the one hand, PRACE calls may allow the usage of resources which are not available in Germany (such as certain types of CPUs or GPUs) while on the other hand, project may apply for access to extreme levels of computing time.

Glossary of Terms