Allocations at TACC

TACC enhances the research and education of the computational science community at UT and its partners by providing access to advanced computing technologies. TACC's unique and valuable resources include high-performance computing, scientific visualization, and data storage systems. The policies and procedures we have implemented to ensure a fair and efficient allocation of these resources are described below.

All TACC resources are allocated on a project basis to a single principal investigator (PI). Faculty and research staff can serve as TACC project PIs. Graduate students, postdoctoral researchers, and undergraduates should have their advisor assume the responsibilities of project PI and submit the allocations request.


Allocations on TACC resources are available to faculty and staff at UT Austin, UT System, TACC Partner Institutions, Texas higher educational institutions and to US academic researchers through the NSF-funded XSEDE project. Eligible UT Austin, UT System, TACC Partner, and Texas higher education users can request TACC allocations or XSEDE allocations; other US academic researchers must request XSEDE allocations.

Allocations on TACC resources are also available to members of the Global Academic Supercomputing Consortium (GASC) program and individuals and groups that engage in collaborative research and development activities with TACC. The TACC industrial affiliates program, Science and Technology Affiliates for Research (STAR), also provides allocations on TACC resources.

Allocation Request Limits

Table 1 lists the maximum allowable SU request per type of allocation, as well as the metric used, either node-hour or core-hours, when calculating SUs per HPC resource.

Table 1. Allocation Request Limits per Project type

Resource Service Unit Metric Startup Instructional Research
Stampede2 node-hours 2100   24,000
Lonestar5 node-hours 2,400 2,400 20,000
Maverick core-hours 10,000 10,000 300,000
Wrangler node-hours 1,000 1,000 1,000

Allocation/Project Types

TACC offers three types of project allocations: startup, instructional, and research. You can request Startup and Instructional allocations at any time throughout the year. Research allocation requests are reviewed quarterly by committee and (see Table 5).

Startup Allocations

Startup project allocations are meant to provide the PI with adequate allocation to build a case for a research or instructional project. These projects will typically receive small allocations with short durations. PIs can apply for a startup project allocation at any time.

Instructional Allocations

Instructional project allocations support academic classes, with limited allocation sizes and for only certain TACC resources. Instructional project allocations will last for the duration of the class plus 14 days.

Requests for allocations on all TACC resources must be made using the TACC Allocations Request System. This includes TACC high performance computing systems, visualization resources, and storage systems. If awarded an allocation, the PI will receive a login and initial password with which to access the appropriate resource. The PI can then create additional logins enabling other members of his/her research group to have access to the resource. However, the PI is responsible for ensuring that all users on the project allocation use TACC resources in accordance with the TACC Usage Policies. Failure to do so can result in immediate cancellation of the allocations and closure of the logins.

Users are expected to become familiar with the information in the User Services sections of the TACC web site in order to select the appropriate type and amount of TACC resources.

Table 2. Startup and Instructional allocation request limits

Resource Startup Instructional
Wrangler up to 1,000 (Node Hours) & 5 TB Storage up to 1,000 (Node Hours) & 5 TB Storage

Research Allocations

Research project allocations support the computational needs of the scientific community. Research project allocations begin on calendar quarters, are normally for one year, and must be renewed annually for multi-year projects. Requests for new research allocations and renewals must be submitted 30 days prior to the start of the allocation period. Requests submitted after the due date will be considered for the next allocation period. PIs can apply for startup project allocations until the next research project quarterly deadline. Multi-year research project allocations can be granted as part of proposal submission by negotiation with TACC during proposal preparation. Such multi-year allocations are also reviewed annually to ensure continued need and effective utilization of the resource.

Table 3. Research Allocation Request Limits

Resource Max Individual Request Requires Committee Review
Stampede 500,000 500,001 - 1,000,000
Wrangler 1,000 (Node Hours) & 5 TB Storage 1-1,000 (Node Hours) & 0-5 TB Storage


When applying for an allocation on an HPC or Viz system you will be asked to estimate the number of service units (SUs) you will require for the project. SUs are calculated based on the wall-clock time of your jobs (measured in hours) and the amount of cores or nodes, depending on the system, used to run a job. Each job run on the resource consumes the SUs allocated to a project.

Table 4. TACC Compute Resources Service Units

TACC Compute Resource Service Unit Metric Job Accounting Formula
Stampede2 node-hours SUs charged = (Number of nodes) X (job wall-clock time)
Maverick core-hours Number of cores X wall-clock time of job
Wrangler node-hours SUs charged = (Number of nodes) X (job wall-clock time)
Lonestar 5 node-hours  
Jetstream vCPU  

Scientific Visualization

An ACES Vislab allocation includes accounts on one or more Vislab rendering systems. To apply for an ACES Vislab allocation, consider which rendering systems your project requires and estimate the number of hours you will need to reserve the ACES Visualization Laboratory. If you are a new user of the facility, you will be required to attend an orientation training session before logins will be activated.

An allocation on the Visualization & Data Analysis cluster, Longhorn is requested seperately from Vislab resources. In estimating the number of SUs to request on these clusters, consider the number of core hours you will require for you visualization needs.

Data Storage

All users of active projects automatically receive an allocation on the TACC's data archive system (Ranch). Currently there is no quota for individual users or projects on the archive system. However, during the allocation request process you will be asked to estimate the amount of archive disk space your project will require.

To use Corral, TACC's Data Applications Facility, you will need to provide the amount of storage required over the life of your project. A quota will be set based on your request but you will be able to request additional space through the allocation process. This space will NOT be backed up or purged; you must move or copy data to the data archive system if retention is desired. See the Corral User Guide for details on storage limitations, costs and protected data types.

The duration of a Data Applications Facility allocation will be one year. Users can apply for an allocation renewal at the end of the period. Failure to apply for a renewal will result in deletion of all data and the space will become available for use by other users.

Applying for an Allocation

To apply for allocations on TACC systems, request project allocations using the TACC Allocations Request System available through the TACC User Portal: Allocation requests are reviewed four times per year according to the following schedule of deadlines.

Table 5. Annual Research Allocation Request Deadlines

Allocation Period New/Renewal Request Due By
January 1 - December 31 December 1
April 1 - March 31 March 1
July 1 - June 30 June 1
October 1 - September 31  September 1

Allocation Management

PIs can add users to their projects by requesting additional login identifiers via the TACC User Portal. Using the portal, PIs can also request new project allocations, update existing project information, and request additional allocations for current projects. Future portal enhancements will enable the PI to view allocation usage and balance information for all projects and users.

Last update: February 6, 2018