Getting Started

The Department of Energy (DOE) Office of Science has three programs by which HPC time is allocated: INCITE program, Director’s Discretionary, and the ALCC program.


The mission of the INCITE program is to enable high-impact, grand-challenge research that could not otherwise be performed without access to the leadership-class systems, Mira, Summit, Theta, and Titan. This typically means that research teams can demonstrate effective use of Mira, Summit, Theta or Titan for production simulations. In other words, for the purpose of scientific or technological discovery, your research requires very, very large compute resources: for example, on the order of 40K processors.

INCITE has an annual call for proposals and dual review process that examines both computational readiness and potential for impact. In CY 2019, we expect to award in total approximately 16M Summit node-hours, 56M Titan node-hours, 184M Mira nodes-hours, and 13.5M Theta node-hours in the INCITE program. For each resource, allocations are anticipated to be between 300k and 800k Summit node-hours, 2M and 5M Titan node-hours, 13M and 25M Mira node-hours, and 1M and 2M Theta node-hours.

INCITE eligibility is very broad. Researchers around the world may apply for time: collaboration with U.S.-based researchers is encouraged but not required. Although the centers are funded by the U.S. Department of Energy, DOE funding is not a prerequisite for application.

Summary: INCITE is for researchers who need – and can effectively use – large scale compute resources for very high-impact research.

Director’s Discretionary

The OLCF and ALCF each allocate ten percent of their available resources on Titan, Mira, Theta and Summit through Director’s Discretionary programs.

See the Related Links under Contact for specific details about requesting time.. Basically, the Director’s Discretionary program is a way for you to request access to the Titan, Mira, Theta and Summit systems in order to carry out porting, tuning, scaling, and other development work, typically in preparation for a future INCITE submittal. Researchers can also request time to carry out benchmarking, since INCITE requires benchmarking data carried out on Titan or Mira or a system of similar architecture.

Researchers around the world may apply for Director’s Discretionary time. The most successful proposals demonstrate that the research team has a clear understanding of the requirements for petascale computing and have the resources to carry out the development work (for example, code modifications) required to make the transition to OLCF and ALCF leadership-class systems.

Summary: Director’s Discretionary is for researchers who are getting ready to submit an INCITE proposal, and need the time to prepare and tune their project for maximum effective use of the leadership systems at the OLCF and ALCF.


The ALCC, or ASCR Leadership Computing Challenge, is a program managed by the U.S. Department of Energy. Through this program nearly thirty percent of the available time on Mira, Summit, Theta, and Titan is allocated. The mission of the ALCC is to award time for special situations of interest to the Department with an emphasis on high-risk, high-payoff simulations in areas directly related to the Department’s energy mission in areas such as advancing the clean energy agenda and understanding the Earth’s climate, for national emergencies, or for broadening the community of researchers capable of using leadership computing resources. For additional information about this program, see the ALCC web site.