The use of HPC facilities offers both free/unpaid and premium/paid compute resources.
Free compute resources are available to all staff and students after signing up for a new HPC Project.
There are no restrictions placed on the resources you may use or jobs you may run in total, beyond the percentage of those resources (nodes, cores) allocated to the free partition/queue, there is a comparatively greater percentage of resources reserved for users/projects with funding (generally the figure varies between 75% / 25% and 80% / 20% depending on node type).
If you want a higher throughput, more simultaneous nodes or to get your jobs to (potentially) scheduled more quickly then the premium compute resources offer an opportunity to do so.
Access to the entire range of premium compute resources requires that your HPC Project has a positive financial balance.
Projects which have not included costs for the use of HPC, or have no funds to call upon can always access the HPC facility, but are restricted in which partitions/queues they can use, and therefore the amount of resources they are able to consume. Partitions are split into free and premium/paid variations, and identified with the _free or _paid suffix. For example:
Not all partitions are available in a free variant. You can check the HPC Resource List (or access the link under 'Accessing Our Facilities' in the top site menu) to view which resources are available for free or paid use.
In general terms, the premium/paid version of a partition will have more hardware resources available (more cores, more nodes) and, potentially, shorter job queue times.
To apply for access to premium/paid compute resources, you must already have an HPC project, or apply for one.
At the point of requesting your new project, indicate that the project has funding available (this is a drop-down option in the project request screen) rather than the default option of being unfunded. Upon approval of your project, a member of the Research Software Engineering team will contact you and establish:
Once these have been confirmed, your HPC project will be configured to access premium partitions in the next upload to the HPC facility.
You should have spoken to the Research Software Engineering team, or used the Contributions & Costings calculator (available under the 'Accessing Our Facilities' site top menu bar) to generate an indicative budget for your use of premium resources before applying for premium access.
Note: If you have an existing HPC project and want to upgrade it to premium/paid access, please contact the Research Software Engineering team and we will do this for you.
Billing for the use of premium compute resources will occur a full month in arrears. To be clear, the billing for all activity started in March shall be issued at the end of April; this allows for the completion of any activity which started in March but continued in to April.
All compute jobs must be submitted with an account code (Slurm option –account=) or they will not be accepted. This should normally be the name of the unix group that the job is being run under. Users who are members of multiple groups should use the relevant group name for billing purposes to avoid costs being allocated to the incorrect group.
Compute resource utilisation data will be updated on a nightly basis within the HPC portal and made visible to all members of the project. You can access the utilisation data for your project over a given month or year via the 'My HPC Projects' page.
All utilisation is tracked. An indicative figure for the use of free compute resources is always given, but this will never form part of your billing.
If a project balance falls under X% of its initial funds, a warning message will be sent to project owners to notify them that access to premium compute resources may be revoked if resource utilisation continues, or the project balance is not increased.
Revocation of access to premium compute resources occurs at the end of a week (a week being defined as Mon-Sun).
Projects which have zero, or negative balance at the start of a new week will lose access to the premium resource areas until their balance is increased.