Computing Services

Service Details

You can access ICS-ACI either by purchasing a Guaranteed Response Time (GReaT) allocation or by using the ICS-ACI Open Queue.

Want to try out the system before you decide which access model is right for you? Request a 30-day trial of ICS-ACI using the Try-ACI button on the right sidebar.

Guaranteed Response Time (GReaT)

A GReaT allocation lets you access as many basic-, standard-, or high-memory compute cores as you need for your research, within a time frame that you choose. With a fully executed Service Level Agreement, any jobs that you submit within your allocation limit are guaranteed to start within one hour of when you submit them.

Other benefits include:

  • No wall time limit
  • Burst capability (use up to 4x your allocated compute for a limited period)
  • 5 TB of Group storage for:
    • Basic-memory allocations with a minimum of 40 cores
    • All other compute allocations with a minimum of 20 cores

With a GReaT allocation, you can choose to purchase access to several different core types, including Basic, Standard, High-memory, and GPUs. You can also purchase additional storage for your research group.

To request a GReaT allocation, contact Derek Leydig. Learn more about GReaT services and rates here (requires Penn State login).

The ICS-ACI Open Queue

Researchers who do not have an allocation can access ICS-ACI through the Open Queue. All you need is an ICS account. If you don’t have one, request an account here.

Jobs submitted to the Open Queue run using idle ICS-ACI computing resources. That means the jobs you submit to this queue do not count against your allocation.

Please note:

  • All ICS-ACI users have equal priority for Open Queue access
  • Open Queue jobs have no guaranteed start time
  • Jobs and interactive sessions will start and run only when sufficient idle cores are available
  • Jobs may be suspended or pre-empted if cores are needed for jobs on other queues

For each ICS-ACI account, Open Queue has these maximum limits:

  • 100 jobs pending
  • 100 cores executing jobs at any given time
  • 48-hour job wall-times
  • 24-hour interactive session durations


The video above provides a brief introduction to using the Open Queue. If you have any questions about using the Open Queue or submitting jobs, please contact iask@ics.psu.edu.