Why and how?

Why and how?#

Why use a supercomputer?#

  • Computing resource needs:

    • CPU and GPU time

    • Memory

    • Storage

  • Ready computing environment, pre-installed GIS-tools

  • Run several computations at same time

  • Spatial data availability

  • Fast internet connection to data services

  • Collaborate with your project members

  • “Outsource” heavy computations, keep own computer for other usage

  • Good documentation, examples for spatial data analysis

  • CSC specialist support

  • Free of charge for open science at Finnish universities and research institutes.

How to use supercomputers?#

Graphical tools -> scripts#

  • Main work is done with scripts

  • Also graphical tools available on supercomputers, but mainly for viewing input and output files

  • Many graphical tools also have scripting options, see GIS tools for more info.

  • Scripts also increase reproducibility of your work

Faster computing#

  • Running most common GIS scripts will be as fast on supercomputer as on laptop

  • To speed up use parallel computing or GPUs.

    • Most GIS-tools have no GPU-support, so the main option is to use parallel computing

    • Deep learning libraries run much faster on GPU.

Parallel computing#

  • Only few GIS tools have built-in support for parallelization

  • By using scripts and dividing the data, any tool can be run in parallel

Embarrassingly parallel analyses#

  • Many similar, but independent tasks.

  • Tasks split by:

    • Input data: map sheets, rows in a dataframe, data from different time periods etc.

    • Analysis parameters: different scenarios, different variables etc.

  • Note, that especially with map sheets extra care might be needed for border areas, for example use overlapping map sheets with virtual rasters.