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Note that Helios uses PLGrid accounts and grants. Make sure to request the "Helios access" access service in the PLGrid portal.

Helios is using the node job-exclusive policy. This means that nodes are allocated for a dedicated, single job which is using the resources. This also impacts the accounting where the minimum amount of resources used equals to one node.

Helios is a hybrid cluster. CPU nodes use x86_64 CPUs, while the GPU partition is based on GH200 superchips, which include an Nvidia Grace - ARM CPU and Nvidia Hopper GPU. HPE Slingshot is used as an interconnect. The login01 node uses an x86_64 CPU and RHEL 8, please . Please keep this in mind when compiling software, etc. Knowing the destination CPU architecture and operating system is important for selecting the proper modules and software. Each architecture has its own set of modules, in order to see the complete list of modules you need to run module avail on a node of a chosen type. Node specification can be found below:

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The same principle was applied to GPU resources, where the GPU-hour is a billing unit, and there are proportional memory per GPU and proportional CPUs per GPU defined (consult the table above).

Note that Helios uses a job-exclusive policy, and currently, minimal resources assigned for a job equal to one node. The job will be billed at the minimum for a whole node (192CPUs on CPU and 4GPUs on GPU partition)!

The cost can be expressed as a simple algorithm:

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Applications and libraries are available through the modules system. Modules for ARM and x86 CPUs are not interchangeable, and selecting the right module for the destined architecture is key critical for getting software to work! Please load the proper modules on the node, inside of the job script! The list of available modules can be obtained by issuing the command:

module avail

This command should be run on a compute node to get a full list of modules available on the given architecture (node type)! The list is searchable by using the '/' key. The specific module can be loaded by the add command:

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Modules' names on Helios are case sensitive.

Sample job scripts

Please note that using bash option -l is crucial for running jobs on Helios, especially on plgrid-gpu-gh200 partition. Please use the following shebang:

#!/bin/bash -l

in your scripts. Example job scripts (without -l option for Ares compatibility) are available on this page: Sample scripts

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