A High Performance Computing (HPC) cluster is a shared scientific infrastructure that provides a large amount of computing resources for research projects.

At the University of Geneva, the HPC infrastructure is operated as the Baobab HPC Service and consists of three HPC clusters: Baobab, Yggdrasil, and Bamboo.

As Baobab was the first HPC cluster deployed at the University and remains the most well-known among our users, we chose to use its name to designate the entire HPC service.

This page is intended for Principal Investigators (PIs) and explains how Billing Units (BU), our unified measure of computing resource usage, are allocated to research groups, how consumption is monitored, the costs associated with HPC usage, and the options available for purchasing or renting private compute nodes.

The HPC service is free in specific situations:

• Educational courses can use the platform free of charge.
• Each Principal Investigator (PI) receives an annual allocation of free Billing Units (BU).

Additional usage can be covered through:

• Pay-per-use billing according to the SNSF pricing table.
• Purchasing or renting compute nodes, which provides additional annual Billing Units and higher scheduling priority.

The HPC accounting model is based on a single resource unit called the Billing Unit (BU).

1. Every PI receives 100,000 BU per year free of charge.
2. Research groups that own or rent compute nodes receive additional annual BU allocations.
3. CPU, memory, and GPU usage are converted into BU using standardized conversion factors.
4. BU can be consumed on any of our HPC clusters: Baobab, Yggdrasil, and Bamboo.
5. Once all available BU have been consumed, additional usage is billed according to the SNSF pricing table.

Research groups may receive Billing Units from two sources:

• 100,000 Billing Units annual free allocation provided to every PI.
• The hardware owned or rented by the research group.

You can check your available BU using:

Resources Available for Research Groups (HPC account or group member with HPC access required)

If your research group owns compute nodes but your PI does not appear in the report, please contact the HPC support team.

Billing Units are tracked annually from December 1 to November 30.

For example:

Monthly reports, annual allocations, remaining balances, and any applicable charges are calculated using this accounting period.

This unified accounting system allows all resources to be compared and billed consistently, regardless of the underlying hardware.

PIs who wish to prevent their research group from exceeding its annual Billing Unit (BU) allocation may request the activation of resource usage limits on their research group account.

When enabled, these limits are enforced by the HPC scheduling system and can help avoid unexpected overconsumption.

Please contact the HPC support team if you would like this option to be enabled for your research group.

Overview of the SNSF HPC pricing table:

You can download the complete table here, Please note that the SNSF rate table will be updated soon to reflect the new Billing Unit (BU) terminology:

SNSF Pricing Table

University of Geneva users are billed according to category U1.

Categories U2 and U3 apply to external organizations such as companies and non-academic institutions.

To ensure fair and predictable pricing, annual resource consumption is evaluated using two pricing models:

• Standard BU pricing
• Compute node rental pricing

At the end of the billing period, the lowest-cost option is automatically applied.

A standard CPU compute node costs 3,303 CHF/year and provides approximately 1,342,848 BU/year.

More details are available in the Cost of Renting a Compute Node section.

This mechanism can substantially reduce costs for research groups with sustained resource consumption while providing a predictable and transparent billing model.

Research groups may purchase or rent compute nodes that are integrated into one of the HPC clusters.

These nodes provide:

• A private partition with higher scheduling priority.
• Reduced queue waiting times.
• Maximum job runtimes of up to 7 days instead of 4 days on public resources.
• Additional annual Billing Units associated with the hardware contribution.

Although the hardware is physically attached to a specific cluster, the associated Billing Units can be used across Baobab, Yggdrasil, and Bamboo, including GPU resources.

To preserve the shared nature of the infrastructure, research groups may consume up to 60% of the theoretical annual resource contribution of the hardware they own or rent.

Example for a compute node with:

• 128 CPU cores
• 512 GB RAM
• 1 year contribution period

Calculation:

• CPU contribution: 128 × 1.0
• Memory contribution: 512 × 0.25
• Time period: 24 × 365
• Usage factor: 0.6

Result:

(128 × 1.0 + 512 × 0.25) × 24 × 365 × 0.6 = 1,342,848 BU

The resulting allocation (1,342,848 BU) can be consumed on any cluster.

The purpose of this model is to ensure fair sharing of the infrastructure while rewarding groups that contribute hardware resources.

• Shared Integration: The node is integrated into the cluster and remains available to other users when not used by the owning group. See Partitions.
• Usage Policy: Usage is governed by the 60% allocation rule described above.
• Administrative Access: Research groups do not receive administrative access to compute nodes.
• Maintenance: Installation and operational maintenance are handled by the HPC team.
• Decommissioning: Nodes remain assigned to the associated research group for five years. After this period, they are migrated to the public partition and become fully available to the broader HPC community until they reach obsolescence.
• Warranty Nodes include a 3-year manufacturer warranty.
  • After the warranty period, repair costs are the responsibility of the research group.
  • Diagnostic costs charged by the vendor are estimated to 420 CHF, even if the hardware cannot be repaired.

The monthly rental cost is calculated from:

1. The vendor purchase price.
2. A 15% infrastructure surcharge covering racks, cabling, networking, storage, and operational costs.
3. A 5-year amortization period.

Example:

• Vendor price: 14,361 CHF
• Infrastructure surcharge (15%): 2,154.15 CHF
• Total cost: 16,515.15 CHF
• Amortization period: 60 months

Monthly rental cost:

16,515.15 CHF / 60 = 275.25 CHF per month

Currently, standard rental nodes consist of:

• 128 AMD CPU cores
• 512 GB RAM

Such a node provides approximately 1.34 million Billing Units per year.

• Minimum rental duration: 6 months
• Unused Billing Units are not carried over and expire at the end of the calendar year.
• Custom hardware configurations may be available upon request.

For quotations or additional information, please contact the HPC support team.

Every PI receives a monthly usage report summarizing the group's resource consumption.

The report includes:

• Annual Billing Units allocated to the research group.
• Billing Units consumed since the beginning of the year.
• Remaining Billing Units.
• Current balance status.

A color indicator helps quickly identify the situation:

• Green: the group remains within its allocated Billing Units.
• Red: the group has exceeded its allocation and additional usage may be billed.

Example:

To monitor your group's current resource consumption, consult:

The dedicated user-friendly web page:

Baobab OpenOnDemand Dashboard (HPC account or group member with HPC access required)

or with linux CLI:

Report and Statistics with sreport (HPC account or group member with HPC access required)