XSEDE Allocations Overview

An XSEDE allocation provides access to computing, visualization, and/or storage resources as well as extended support services at XSEDE service provider (SP) sites. An allocation is allotted to a researcher who serves as the principal investigator (PI) of an approved project. An account is the specific method through which an individual (or community, in the case of science gateways) logs in to a resource to utilize the allocation.

  • Computational Resources: XSEDE SPs offer a variety of high-performance computing (HPC) and high-throughput computing systems for allocation. Computing platforms include clusters, scalable-parallel systems, and shared-memory systems with various CPU, memory, communication, and storage configurations. It is important that the platform you choose is a good match for your computational plans.
  • Visualization Resources: SPs provide a variety of visualization resources and software services to the XSEDE user community. These systems provide a powerful way to interact with and analyze data at any scale. For complete information on available visualization resources, visit XSEDE Visualization.
  • Storage Resources: Several XSEDE SPs host storage platforms providing services such as data management, data collections hosting, and large-scale persistent storage. XSEDE will provide storage allocations both in support of compute/visualization usage and storage independent of those compute/visualization allocations. As with compute and visualization allocations, storage allocation durations are one year with the option to renew for subsequent one-year periods. Data will be preserved for at least one quarter beyond the expiration of the storage allocation end date. Retention beyond one quarter will be at the discretion of the SP. Storage is allocated in GigaBytes (GB). Please visit the XSEDE Storage page for more information about available storage platforms.

All XSEDE compute allocations include access to limited disk and scratch space on the compute resource file system to accomplish project goals. Access to persistent, archival storage on companion storage systems must be requested by the PI through the XSEDE Resource Allocation System (XRAS), the same system used to request compute or visualization resources. Storage allocations on stand-alone storage systems, must also be requested through XRAS via the XSEDE User Portal. For more information about available machines, including XSEDE capabilities and recommended use guidelines, please visit the XSEDE Resources page.

Allocation Eligibility

To apply, the principal investigator (PI) must be a researcher or educator at a U.S.-based institution, including federal research labs or commercial organizations, though additional information may be needed from researchers not affiliated with academic or non-profit research institutions. A postdoctoral researcher is eligible to serve as PI. After receiving an allocation, PIs can request that students be given accounts to use the allocation.

In general, XSEDE follows the guidelines described in the current NSF Grant Proposal Guide. However, investigators with support from any funding source, not just NSF, are encouraged to apply. If your institution is not a university or a two- or four-year college, special rules may apply.

Allocation Metrics (SUs)

Computational and visualization services in XSEDE are allocated and charged in Service Units (SUs). SUs are defined locally on each system, with conversion factors among systems. To calculate the conversion of SUs from one XSEDE digital service to another, use the XSEDE SU Conversion Calculator.

Storage resource allocations are made directly in gigabytes. To estimate the amount of storage to request users should consider the size of input files, data sets to be analyzed, and output files generated that need to be retained for future analysis. Users making databases and data collections available to their research teams and for user community access should consider the initial size of the database or collection and consider the likelihood of growth.

Allocation Types

The process for requesting and obtaining access to XSEDE resources differs depending upon the type and purpose of the allocation being requested. XSEDE offers the following allocation types:

Trial Allocations

Beginning April 1, 2015 SDSC will begin offering Trial allocations on the new Comet system.

Trial allocations are designed to give potential users rapid, but limited access to XSEDE resources. Within one business day, users will be able to log on and evaluate an XSEDE resource prior to requesting a larger startup or research allocation. Trial allocation sizes will be limited, but sufficient, for initial resource evaluation. For compute resources it will give new users the ability to compile and run software, and evaluate results, within the XSEDE resource software and hardware environment.

To apply for a trial allocation, create an XSEDE User Portal (XUP) account. Once you have your portal account you can request a trial account via the table below.

Resource Trial Allocation limit Request a Trial Account
Comet 1000 SUs, 6 months Please submit an XSEDE help-desk ticket

Campus Champions Allocations

For those interested in running small tests prior to an allocations request, your site may have a Campus Champion you can contact. Campus Champion allocations are typically for a short time periods, but may be a potentially easier path than applying for a Startup Allocation and can also be an excellent means to get familiar with XSEDE and the allocation process. Click here for contact information.

Startup Allocations

Startup allocation requests are reviewed continually throughout the year, are the fastest way of getting started on XSEDE, and are recommended for all new XSEDE users. Startup allocations are for one year, after which, the PI should request a Research allocation. A PI may have only one active Startup allocation at a time.

Startup Allocations on XSEDE are available to faculty members and postdoctoral researchers at U.S. academic research institutions, as well as to K-12 teachers for classroom use.

Appropriate uses for Startup allocations include:

  • Application development by principal investigators
  • Experimentation on XSEDE platforms
  • Use of XSEDE systems for classroom instruction
  • Developing a science gateway

Startup allocations are limited per resource according to Table 1. For more detailed information please read the Startup & Education Allocation Proposals section under Writing Allocation Proposals below.

Education Allocations

Education allocations are for academic or training classes such as those provided at a university that have specific begin and end dates. In addition to training classes, education projects support classroom instruction. Education allocations are appropriate for academic courses or training classes having a registration number, class description, and known timeframe. Education requests have the same allocation size limits as Startup requests. PIs on education allocations must be faculty.

For more detailed information please read the Startup & Education Allocation Proposals section under Writing Allocation Proposals below.

Research Allocations

Research allocations may be requested for any compute, visualization, or storage resource and require a formal request document and CVs (for PI/Co-PIs). Research allocations are typically appropriate as follow-ons to Startups; but a PI need not request a Startup prior to submitting a Research request. A PI may submit a Research allocation request at any time during an active Startup allocation, if the PI has fulfilled his or her startup needs. A successful Research allocation will supersede any Startup allocation and start a new 12-month allocation period.

The XSEDE Resource Allocations Committee (XRAC) meets quarterly to review requests based on merit and then award available SUs. Requests may be submitted the quarter before they are needed during designated submission windows as listed in Table 2 below.

Table 2. Research Allocation Deadlines

Dec 15 thru Jan 15 April 1
Mar 15 thru Apr 15 Jul 1
Jun 15 thru Jul 15 Oct 1
Sep 15 thru Oct 15 Jan 1

For much more detailed information please read the Research Allocation Proposals section under Writing Allocation Proposals below.

The following recorded presentation details all the requirements needed for successful research allocation requests. Topics covered include Computation Methodologies, Justification for Service Units (SUs) requested and many others.

Writing and Submitting a Successful XSEDE Proposal
Recorded: April 4, 2017
Run time: 1:25:35

Writing and Submitting Allocation Proposals

Startup & Education Allocation Proposals

Startup and Education allocations are easy to request with fast approval time. The request process requires a CV and short abstract; PIs may apply at any time. Startup allocations are appropriate for code development, experimentation with XSEDE platforms, or for application testing. Most first-time XSEDE users begin with a Startup allocation. PIs may request a single computational or visualization resource or a combination of resources. Startup requests may total up to 200,000 CPU-hours (or Service Units, SUs), though limits for individual resources may vary. SPs providing allocatable storage resources consider storage startups in combination with compute and visualization resources and some SPs allow storage-only requests. For resource-specific startup limits view the table above.

The PI should assess the amount of time that will be necessary to accomplish the computational project. If you are just getting started and not certain of your computational needs, then apply for a Startup allocation request. For a project that requires a significant amount of time or data storage, apply for a Research allocation.

Education allocations follow the same process as Startup allocations, save that the PI must justify the need for the resource based not only on its architecture (as needed for each type of project) but also the amount of disjoint work students will perform on the resource (since nodes cannot be shared between users), being cognizant to not exceed the startup allocation limit for the resource. Note the approximate number of students along with the number and approximate computational resource requirements for each project (e.g., one node per student for one hour, etc.).

This information, along with startup allocation limits and the number of SUs charged for sole use of one node (located in each resource's User Guide) should be used to tabulate approximate resource needs for the class as a whole, giving some buffer for errant runs, similar to the discussion in the first example.

If in doubt, 1000-1500 SUs per student per course project where the duration of a project is approximately one hour of compute time is typical; requests that drastically exceed that amount will require significant additional justification. Also, please include a syllabus in your request so that the reviewers have a better idea of what topics you will cover, as is discussed in the first example.

Example Education Allocation Requests

Please click on the links below for pop-up sample Education allocation requests.

Example 1: A Well-Written Education Proposal

Example 2: Sample Proposal A with Suggestions for Improvement

Example 3: Sample Proposal B with Suggestions for Improvement

Research Allocation Proposals

Writing Your Research Allocation Request: Well written requests contain all the information the review panel requires to assess your project qualifications. Details for writing a request to use any XSEDE resource are available in the XSEDE Resource Allocation Policies. Sample Research allocation requests are available as examples of how requests should be presented.

Well written research allocation requests will meet the following guidelines:

  • The research is summarized in context of the current state of the art; outlines the computational algorithms to be used; and relates those algorithms to subsections of the request.
  • Provide sufficent information, without overwhelming details to the reviewers.
  • The justification for the request is clear, and closely coupled to computational experiments and needs, so that if the committee needs to reduce the original request, it can be done rationally with minimum disruption to the investigator.
  • Summarize results from relevant previous allocations, including manuscripts published, accepted, submitted, or in preparation, and relate these results to the current request.

Submitting Your Research Allocation Request: Requests for computing, visualization, and storage allocations must be submitted electronically via the XSEDE User Portal. Users will be notified via email when their allocations are approved or they have been added to an allocation. After a request has been reviewed and allocated, the project's PI will receive an email informing him or her that the account is ready. Notification emails are typically sent two weeks prior to the allocation begin date.

Allocation requests that are not approved will receive email notification. PIs will receive a link to reviewer comments and instructions from the XSEDE Allocations Coordinator. Commonly, PIs are encouraged to rework their proposal and submit again during the next allocation period. Based on guidance from the committee, PIs can resubmit the proposal including additional project information, computational plan details, and better justification for the requested allocation. XSEDE can provide advances on revised proposals to provide PIs with some computing capacity until the next set of allocation request are reviewed and awarded. Or additional time on the PI's Startup project can be provided for work to support the research proposal.

PIs may delegate an allocation manager who can manage their allocations for them. This will be done in the user portal under My XSEDE -> Allocations/Usage

To view a listing of XSEDE allocations please visit the Current & Past XSEDE allocations page.

Last update: April 5, 2017

Table 1. SU Startup Allocation Limits per Resource

Resource name Startup allocation limit (SUs)
Bridges Large 1000
Bridges Regular 50000
SuperMIC 50000
Jetstream 50000
Comet 50000
Wrangler 1000
Quarry 5
Stampede 50000
Greenfield 4000
XStream 5000
Resource name Startup allocation limit (SUs)
Maverick 3000
Resource name Startup allocation limit (SUs)
Open Science Grid 200000