This document states the policies and instructions for preparing requests to use cyberinfrastructure resources on XSEDE. All interested persons are encouraged to review this guide prior to making submission; any questions regarding these policies should be directed to the XSEDE Help Desk. Answers to Frequently Asked Questions (FAQs) are available in the XSEDE Knowledge base.

XSEDE resources are allocated through an XSEDE Project, where an XSEDE Project has a single principal investigator (PI) and may include allocations on one or more resources. The PI uses the same XSEDE Project to request (renew) allocation in subsequent years. That is, the PI maintains the same XSEDE Project, even though the focus and computational projects change from year to year (from one renewal to the next). There are three types of projects.

Principal Investigators (PIs) of research programs should use Research Project Requests to obtain allocations for their computational research. These requests are reviewed quarterly by the XSEDE Resource Allocation Committee (XRAC). The committee consists of researchers and computational scientists who review these submissions and make allocation recommendations for all XSEDE resources. Submissions are due 2.5 months before the quarter.

Startup Project Requests provide a mechanism to new users for starting their research or initial experience on XSEDE resources without delay. Education Projects, support classroom instruction and training classes. Startup and Education projects are accepted and reviewed continuously throughout the quarter. The request form was designed to make application easy, requiring only basic biography information, an abstract and a CV. Details are available on the Requesting a Startup or Education Allocation: Step-by-Step for First-Time Users page.

Support for the acquisition of and/or operation of XSEDE resources is provided by NSF under grant number OCI-0503697 to the Grid Infrastructure Group (GIG) and grants to the XSEDE Service Providers. Any opinions, findings, conclusions, or recommendations expressed in this material are those of XSEDE. Many of the policies have been derived under the direction of the SAB (Scientific Advisory Board) and Quarterly Report Meetings under the management of XSEDE. The allocations procedures and processes are managed and implemented through the XSEDE Allocations group.


Most new changes focus on streamlining the allocation process, providing new features or clarifying the documentation. Any new policy updates that reflect significant changes from prior policies and request preparation instructions will be posted in this section for one year. PIs should review the relevant sections containing updates and the Resource Catalog before their next submission.

1.Storage allocation requests for Archival Storage in conjunction with compute and visualizations resources and or Stand Alone Storage need to be requested explicitly both in your proposal (research proposals) and also in the resource section of POPS.

In an effort to ensure that current and potential users benefit as soon as possible, these policy changes are being rolled out while related changes to the XSEDE's resource request system (POPS) are being implemented. Users should watch for changes to POPS and pay close attention to instructions within the POPS data entry forms.

Appropriate Uses for XSEDE Allocations

XSEDE provides access to resources in high-performance computing, scientific visualization, data storage, and extended collaborative support, to enhance scientific discovery. These policies and procedures are followed to ensure a fair and efficient allocation of these resources.

XSEDE encourages and supports projects in all disciplines for a wide range of purposes. In general, XSEDE allocations policies provide for projects that (1) permit researchers or research groups to evaluate XSEDE capabilities, port codes, and otherwise get started in the XSEDE environment; (2) support a range of educational objectives, from classroom instruction to training classes; and (3) allow individuals or groups to pursue their science and engineering research objectives.


Within this broad scope, XSEDE projects support various categories of research consortiums and services. Most often, XSEDE projects can be classified in one of the following categories:

  1. Single Principal Investigator (PI): Most projects support a single PI and possibly a small research group working closely and co-authoring papers.
  2. Multi-PI, Large Research Collaborations: Projects of this type are characterized by a single PI representing a large group of collaborating co-PIs who are working on sub-projects within the overall collaboration. A single request is submitted, and a single project is allocated. The management of the allocated resources is left to the discretion of the principals on the request.
  3. Large-scale Consortiums: Projects of this type are intended to support large-scale, funded projects that work together as a consortium. Often in these cases, a mechanism already exists for allocating community or project resources (e.g., an instrument such as a telescope or detector), and that mechanism will also be used to make allocations from the time granted to the community project to the individual investigators. Requests for this type of project typically describe the internal processes for managing access of individual investigators within the consortium.
  4. Gateways or Community Services: Projects of this type provide services to a large community of users who are typically not directly collaborating with the project PI. An example of such a project would be an application portal service providing access to software and computer time to a community of biology researchers via a web-based interface. Requests to provide such a service must describe the details of the services provided, the methods used, the expected consumption of resources, and mechanisms for monitoring the users and usage of the service. Statistics of community usage should be reported quarterly and in renewal requests for resources, progress reports, and end-of-project reports. XSEDE provides How to Write a Winning Gateway Proposal to assist in writing these requests.

The principal investigator (PI) of an allocated project is the person responsible for the accuracy of the resource request and the management of the ensuing allocation. This person must be a researcher or educator at a U.S. academic or non-profit research institution. A PI may not be a high school or undergraduate student; a qualified advisor, for example, a high school teacher or faculty member, must serve in this capacity. In most cases, a graduate student may not be a PI; however, see Section 8.1 for an exception for NSF Graduate Research Fellows and Honorable Mention awardees. A post-doctoral researcher is eligible to be a PI.

A U.S.-based scientist, engineer, or educator who has a joint appointment with a university or non-profit research institution may submit a request using that affiliation. The appointment may be adjunct, instructional, or any other official position.

Research staff from federal and state agencies or federally funded research and development centers (FFRDCs) are also welcome to apply for an XSEDE allocation if their agency or center does not typically provide research staff with access to non-XSEDE HPC resources of adequate scope for the planned research. The lack of access to CI resources should be documented in the request, as described in Section 7.3. As above, work not funded by a peer-reviewed grant will be subject to scientific review.

Section 8 lists further categories of individuals who are eligible to request XSEDE allocations. The most common class of ineligible PIs are researchers based outside of the United States. While XSEDE supports collaborations between U.S.-based PIs and their foreign colleagues, PIs on XSEDE requests and allocations must be based at a U.S. institution.

Allocated projects need not be supported by NSF grants; PIs may have support from any funding agency or funding source. Furthermore, while most requests do have peer-reviewed funding awards, a PI need not have such a grant in order to submit resource requests; however, the scientific merit of requests for use in research not supported by peer-reviewed funding will be evaluated by XSEDE reviewers. See Section 7.1.

3. General Allocation Policies

To support the wide range of research objectives and project uses described above, the XSEDE allocations process defines three types of projects.

  1. Startup: Startup projects target new users planning to submit more substantial requests in the future as well as users who have modest computational requirements that, nevertheless, cannot be satisfied by their campus resources.
  2. Education: Education projects target faculty or teachers intending to use XSEDE resources for classroom instruction or training classes related to the use of advanced cyberinfrastructure technologies.
  3. Research: Research projects are designated for projects that have progressed beyond the startup phase and are conducting production usage of XSEDE resources in pursuit of their research objectives.

Details specific to Startup and Education projects, including allocation size restrictions, are described in Section 5. Details specific to Research requests and projects are covered in Section 6. However, projects of all three types are subject to a common, basic set of policies and procedures, which are summarized in this section.


XSEDE makes available a set of cyberinfrastructure resources for allocation requests and awards. In general, these resources can be categorized into computational, storage, specialized, and grid resources. For a full listing of resources and architecture details, please refer to the XSEDE Resource Catalog.

Computational resources are typically HPC systems oriented toward batch job submission. XSEDE includes systems of various architectures and from many vendors. Note that computational resources typically have associated disk systems for short-term data storage by users.

Storage resources include both disk-based systems for medium- and long-term storage of data and tape-based systems for long-term storage. Some storage resources available to users are not part of the allocations process.

Specialized resources include dedicated visualization systems, systems for virtual hosting, and high-throughput Condor pools.

Extended collaborative support resources include staff experts from the XSEDE partner sites whose time is devoted to working with single allocated projects to accelerate the progress of each project toward its research objectives. Extended support may include working on code performance, adapting codes to XSEDE capabilities, improving gateway capabilities, and so on.


Allocation requests for XSEDE resources are only accepted electronically and must be made through the POPS system via the XSEDE User Portal. Requests include annual submissions to initiate or continue allocations as well as manage allocations during an allocation period.

The POPS system recognizes seven types of Request Actions, which can apply to all three types of projects:

  1. New: A submission is considered "new" if it is (a) a PI's first submission to XSEDE, (b) a request in a completely different area of science than a PI's previously submitted requests, or (c) a PI's first request for a particular project type (Startup, Education, or Research). For example, a PI with a prior or current Startup allocation but now submitting a Research request is considered a new Research request.
  2. Renewal: A submission should be a "renewal" if a PI (a) has had an allocation of the same request type, which was active within the past two years, (b) is continuing the same or similar line of research, and (c) is in the same field of science. A renewal request must address the progress of the prior allocation's research.
  3. Supplement: A supplement is a request for additional resources during an existing allocation's one-year time frame. Its purpose is to support changes in the original computational research plan that are required to achieve the scientific goals of the project. This may include altered or new projects or support for projects proceeding more rapidly than anticipated or that require more resources than anticipated (see Section 3.5.3). Supplement awards are highly dependent upon availability of resources and limited when allocation awards at the previous XRAC meeting have been reduced to eliminate oversubscriptions. Supplements are not a mechanism to acquire additional resources for awards that were granted for less than the amount originally requested (see Justification for information on appealing reduced awards).
  4. Transfer: Transfers (Section 3.5.5) of allocated units between XSEDE resources are requested through POPS. No formal documentation is required.
  5. Extension: Extensions (Section 3.5.6) of allocation periods beyond the normal 12-month duration are requested through POPS. A brief reason is required but no formal documentation is needed.
  6. Justification (Appeal): If the XRAC has requested that the PI give more details or justification before the project can be allocated any time or any additional time, the PI should submit a justification (appeal). Also, a PI may submit a rebuttal on a review criticism as a Justification (Appeal) request. This type of submission should specifically address information that the reviewers have requested or have criticized. (See Section 6.4.4) This request type does not apply to Startup or Education requests; PIs for those types should submit another, revised Startup or Education request.
  7. Advance: You can request an advance of up to 25% of your submitted Research request. Usage against this advance will be deducted from your eventual allocation award. In addition, approval of the advance is subject to XSEDE review and the availability of sufficient units on the selected resource(s).

An individual should generally be PI on only one active XSEDE resource request/project at a given time. Several distinct research activities can be combined in a single resource request, however, the resource request for each activity must be justified, and any allocation-size limits apply to the aggregate request.

The single-project rule is designed to minimize the effort required by PIs for submitting resource requests and the overhead to the XSEDE process for reviewing those requests. While PIs may have several different funded grants that require computational support, these should be included as sub-projects within a single request.

There are several exceptions to this rule:

  • A PI may submit a Research request at any time during an active Startup allocation. A successful Research allocation will supersede any Startup allocations and start a new 12-month allocation period.
  • If a PI has research activities that are in significantly different fields of science and, therefore, cannot be reviewed by the same set of reviewers, multiple requests/projects will be considered.
  • If a PI is leading an individual research activity as well as a community consortium activity or community service activity, separate requests for these distinct activities will be considered.
  • A PI with active Startup or Research projects may submit requests for any number of Education projects to keep classroom and training users separate from research activities.

Similarly, to minimize the effort required to gain access to XSEDE resources, closely collaborating researchers should submit a single collaborative request rather than several individual requests. For example, a PI and associated post-doctoral researchers; investigators supported by the same funding grant; and researchers in the same lab group should consider submitting a request describing and justifying the various subactivities. One of the collaborators is designated as the PI, and others can be designated as co-PIs. For further guidance on whether multiple requests or a single, collaborative request is appropriate in a specific case, please contact the XSEDE Help Desk.


All allocations for XSEDE resources are made for a 12-month period. PIs can continue their activities in subsequent years through annual renewal requests (Section 3.5.1).


At the end of each 12-month allocation period, single- and multi-year projects forfeit any unused compute SUs. For storage allocations that have used less than their allocated space, a PI must justify continued need for the extra space or risk a reduced allocation amount in subsequent years. However, see Section 3.5.6 below.


Once a project has received its allocation, XSEDE gives the PI and any co-PIs a number of options to ensure the flexibility needed to complete their research objectives.


The most important consideration for PIs is whether they wish to continue computing after the expiration of their current allocation period.

In general, Startup allocations are not eligible for continuation or renewal; PIs are expected to submit Research requests to a XRAC meeting during their Startup allocation period to continue pursuing their research objectives. Certain exceptions apply; see Section 5.2.

For single-year Research awards, the PI should submit a Renewal request to the XRAC for consideration. In most cases, they should submit this request approximately one year after their initial request submission, so that it can be reviewed and awarded to avoid any interruption. In general, the appropriate submission period is the one approximately three months prior to the expiration of their allocation.


A PI may share his/her allocation by establishing accounts under the allocation with any number of collaborators, including graduate or undergraduate students. Research collaborators may include colleagues based outside of the U.S. Additional users can be added through the XSEDE User Portal (under the My XSEDE tab).

PIs on Education allocations can contact the XSEDE Help Desk for assistance in establishing accounts for large groups of students under their allocated project.


To request additional resources during an allocation award period, a PI may submit a Supplement Request for resources through POPS via the XSEDE User Portal. Supplement Requests are accepted at any time and are generally considered within two to three weeks of submission. However, large requests must be reviewed by the panel along with new and renewal Research requests at the next XRAC meeting. Generally, supplemental allocation requests for startup awards are capped at the startup award limits for the particular resource; however, all other supplemental allocation requests have no limit.

The Main Document of the Supplement Request should contain the following: minimal information about the science and methodologies concerning the supplement; a description of new projects or why more resources are needed to complete the project in progress; a work plan that includes justifications that detail the new costs for computations; and any new efficiencies in codes or methods.

Do not upload the Main Document of the original request. Since a Supplement Main Document addresses the concerns of only an additional allocation is should be appropriately short compared to the Main Document of the original request and no greater than five pages.

A Progress Report is also required and should contain the following:

  1. New scientific discoveries
  2. Computational accomplishments of the previous computational work plan (list and SUs used)
  3. Summary of publication information, including conference presentations, technical reports, etc. (Put the Publication list in a separate document, but report the number of publications and other proceedings and reports in the Progress report.)
  4. Contributions to other research efforts and fields of science (experimental/computational/instrumental, etc.).

In practice, to ensure a group can continue computing without an interruption, a PI should not wait until an allocation is completely spent before submitting a Supplement request. Please allow at least two to three weeks for review and processing.

Supplemental allocations to Startup and Education projects are constrained by the allocation-size restrictions on these projects (see Section 5). PIs should submit Supplement requests via the POPS system.


Upon submitting a new or renewal Research request, PIs are allowed to ask for an immediate advance of up to 25% of the resources requested in anticipation of favorable review. The size of the advance will depend on current availability on the target resource and staff review. Any usage of this advance will be debited against the eventual allocation. Advances are accepted up to three weeks before the upcoming allocation period.


PIs can request that allocated time be transferred from one platform to another, subject to resource availability on the target resource. On Research allocations, such transfers are subject to conversion of SUs according to established weighting factors (see Section 4.2.2). On Startup allocations, transfers are subject to the size restrictions for the target resource (see Section 5). PIs must submit transfer requests via the POPS system.


Projects that encounter problems in consuming their allocations, such as unexpected staffing changes, can request an extension to their allocation end date. In such instances, PIs may request a single extension of an allocation, extending the expiration date by a maximum of six months The PI will be asked to specify the project number and the length of the extension (1-6 months), along with a brief reason for the extension.

Note that Extensions apply to all current resource allocations on the same project; PIs cannot extend some allocations and submit overlapping Renewal requests for other resources.

If a project still has unused allocation units at the end of the extended allocation period, the PI must submit a Renewal request to continue their XSEDE project; the request should explain the reasons for the unused allocation.

Extension requests should be submitted via the POPS system.


An acknowledgement of support from the appropriate service provider and XSEDE should appear in any publication of material, whether copyrighted or not, that describes work which benefited from access to XSEDE cyberinfrastructure resources. For suggested language, see How to Acknowledge XSEDE.

PIs should include a bibliography of articles or other manuscripts - published, accepted, submitted or in preparation - that benefited from support by XSEDE resources as part of their annual Progress Reports and Final Reports (see Section 6.3.2).

4. Selecting Resources and Calculating Allocation Sizes

PIs who need the special capabilities of particular XSEDE resources can specify those resources in their requests. This section contains information related to selecting resources and calculating allocation amounts for all requests.


For each resource available for allocation, a statement of recommended use is available in the XSEDE Resource Catalog. These guidelines describe Service Provider policies or usage models that may be emphasized or, conversely, may not be permitted on certain resources. PIs are advised to review these guidelines before submitting requests for specific resources.


The requested allocation amounts for XSEDE resources need to be detailed and justified in the supporting documents. Allocation amounts for compute, storage, and/or advanced support resources should be clearly linked to the scientific goals and the proposed research plan.

  • For compute resources, calculations should be based on small-scale test runs on the resources of interest and scaling tests, as well as the number and type of runs to be made.
  • For storage resources, calculations should describe the data to be stored and the amount of storage required for the data (record/file size, number of files/records, and/or other relevant characteristics). Storage resource allocations are made directly in gigabytes.
  • A request for Extended Collaborative Support Services (ECSS) to enhance the effectiveness and productivity of work can accompany an application for resources at any level, or it can be submitted stand-alone as a Supplement to an active grant. It requires the Principal Investigator (PI) to answer five (5) questions in the Resource request section of POPS. This request will be reviewed, usually in conjunction with your XSEDE grant proposal. ECSS management will then assess whether there is also a good potential match with the experts available to collaborate with your team. For more information please visit the ECSS page.

Different resource types define different units for making resource requests. The XSEDE Resource Catalog shows the allocation request unit for each resource. Throughout the remainder of this document, the following resource types and allocation units are used:

Compute resources (including most visualization resources) are requested in terms of "service units" (SUs). In general, 1 SU equals 1 processor core-hour, or one wallclock-hour on one processor core, on a given resource. Local resource policies may define more complex formulas for SUs that include such factors as queue priority and so on. A submission that requests allocations on several resources should specify each of those requests in terms of local SUs.

Storage resources are requested in terms of gigabytes (GBs).

Extended Collaborative Support is requested in terms of FTE-Months, generally an estimate of the expected duration and level of XSEDE staff support needed. These estimates may later be revised upon interaction with the relevant XSEDE staff.

Specialized resources may define specialized request units. Refer to the XSEDE Resources Catalog for the units used in requesting allocations on these resources.


When allocated units are transferred from one compute resource to another, a conversion is applied to normalize the relative computational power of the two resources. The most common situation is a transfer of SUs from one compute resource to another. In this case, the standard conversion is based on a formula derived from the resource's performance on the HPL benchmark. Users can review the standard conversions using the SU Conversion Calculator.

Alternate conversion rates. If a PI has performance results of his/her group's own code on the source and target resources in a transfer request, the PI can request a conversion factor based on that code's performance be applied. The alternate conversion rate should be documented and noted in the transfer request.

At this time, it is not possible to convert allocable units on one resource type to units on another resource type. For example, storage allocations cannot be converted to compute allocations.

5. Startup and Education Requests

To enable researchers to quickly gain access to XSEDE resources, XSEDE provides two small-scale project types, both of which require only a project abstract.

  • Startup projects target researchers getting started on XSEDE, developing code, testing applications, and other similar purposes. PIs making Startup requests can select from a full list of XSEDE resources.
  • Education projects are specifically designated for class instruction or training activities.

Education requests present requesters with those XSEDE resources that Service Providers have made available for classroom or training activities.

Given the difference in sizes of the new XSEDE HPC systems, Startup and Education allocations can be as much as 200,000 SUs on the largest systems. The limit on the smaller systems ranges from 1,000 to 50,000 SUs. The grand total number of SUs in a Startup or Education request cannot exceed 200,000 SUs. The Startup allocation limit will be posted in the XSEDE Resource Catalog for each resource. In addition, transfers to a single resource on a Startup allocation cannot exceed that resource's Startup limit. The XSEDE reviewers and allocations staff will enforce these limits. Startup and Education allocations are for a period of one year beginning at the soonest practical date following a review of the request. They end 12 months later.


Startup and Education requests can be submitted at any time via the POPS system. The requests are reviewed and processed continually. An individual request is typically reviewed and processed within two weeks of submission.

Within POPS, Startup and Education requests primarily require basic information about the PI, any co-PIs, and funding grants supporting the work being conducted. The POPS forms also request an abstract describing the work to be conducted.

An abstract with a general description of the work may be sufficient, but additional information that will enhance your request may include explanations for why the project needs access to XSEDE resources, how the estimate of resources request was reached, and how the resources requested were selected.

A curriculum vitae (CV) for the PI and each co-PI is required. CVs should be in standard NSF or NIH format (two page maximum). The Documents upload section of POPS will expect a CV upload for each co-PI (and the PI) entered in the Co-PI information area. PIs having NSF Fellowship or Honorable Mention awards must attach a copy of their NSF award letter to their request.


In general, Startup allocations are presumed to be for one year only. However, renewals will be permitted with appropriate justification and subject to XSEDE reviewer approval; researchers may be directed to submit Research project requests to the XRAC. Valid rationales for renewing Startup projects may include progress on Startup work that has proceeded more slowly than anticipated, or lack of access to campus resources to support the research activities being proposed even at the scale of XSEDE Startup allocations. This may include the need to access specialized resources or larger-scale resources not typically available on campuses.

Education projects can be renewed indefinitely as long as the education activity - for example, a class repeated each academic year - is continued.

In submitting a renewal for a Startup or Education project, a PI is required to include a Progress Report describing how the prior year's allocation was used and a listing of any publications (published, accepted, submitted or in preparation) that resulted from the prior year's allocation.


Startup and Education requests are accepted at anytime and reviewed by XSEDE staff. Please allow two weeks from submission for review and project creation.

The review process for Startup and Education requests is as follows: Each request will be reviewed by at least one XSEDE staff reviewer, and if the first review rejects the request, a second review will automatically be conducted. For Startup and Education requests, each RP will define a primary reviewer, and the Allocations Coordinator or designee will assign the reviewer from each RP whose resource has been selected by the PI. The EOT Area Director will appoint reviewers for Education requests; XSEDE Extended Collaborative Support Services Area Director will appoint reviewers to evaluate XSEDE Extended Support requests.

PIs for Startup and Education requests are notified by email when reviews are completed.

6. Submitting Research Requests

For projects that have progressed beyond the Startup phase, a Research request is appropriate. Research requests include a well-documented resource-use plan that describes how the requested allocations are necessary and sufficient to accomplish the project's research objectives. A single Research request and resulting project may combine compute, storage and Extended Collaborative Support Services Program requests.

Research requests of all sizes are submitted for consideration to the XSEDE Resource Allocation Committee (XRAC). There is no limit to the size of allocations that can be provided to Research requests; however, the Allocation Coordinator may determine that some smaller-scale Research requests can be processed via staff-only review.


The XRAC submission deadlines are January 15, April 15, July 15, and October 15. These deadlines are approximately six weeks prior to the meeting at which they will be reviewed, and 10 weeks prior to the allocation start date. The corresponding allocations begin April 1, July 1, October 1, and January 1, respectively, and the corresponding allocation end dates are therefore March 31, June 30, September 30, and December 31.

In general, once a PI enters the allocations process, the PI should plan to submit a Renewal request at the same deadline each year to avoid interruption in the project's allocations, assuming they consume their allocation within the 12-month period. (See, however, Section 3.5.6 on extending projects that are proceeding more slowly than anticipated.) All potential and continuing Research projects are encouraged to keep these deadlines in mind for their planning purposes.


The following elements are entered directly into POPS web forms as part of the submission. Since they are entered in the POPS forms, these elements need not be repeated within the request documents.

  • PI and Co-PI Information: The entries consist of the standard cover sheet information regarding the PI and any co-PIs.
  • Project Information: The project title, relevant field(s) of science, the project abstract and keywords. Accurate primary and secondary fields of science ensure that a request can be assigned to experts within the appropriate domain.
  • Supporting Grants: Information regarding any grants, awards, funding or other support provided to accomplish the goals of the submitted request. These should be the annual dollar amounts that have been provided for support to the entire project, not just the budget for computing-related activities. If the supporting grant funds activities beyond those proposed for XSEDE resources (such as experimental work, or work by other collaborators), the PI can specify the percentage of the annual funding for the grant that will be associated with the activities to be supported by XSEDE resources.
  • Resource Request: The resources being requested, along with a summary of the resource needs (i.e., responses to the questions associated with each resource).
  • Request Documents: For Research submissions, specific documents are required as described in Section 6.3. While POPS accepts several file formats, PDF files are recommended.

The supplied documents must discuss the work planned, justify the resource request, and provides any relevant additional information (e.g., Special Requirements or Code Performance and Scaling). The Main Document must adhere to page length rules. See Section 7 for guidelines in crafting a successful submission.


While readability is of greatest importance, documents must satisfy the following minimum requirements. Documents that conform to NSF proposal format guidelines will satisfy these guidelines.

Margins: Documents must have 2.5-cm (1-inch) margins at the top, bottom, and sides.

Fonts and Spacing: The type size used throughout the documents must conform to the following three requirements:

  • The font size must not be smaller than 10 points.
  • Type density must be no more than 15 characters per 2.5 cm (1 inch).
  • No more than 6 lines must be within a vertical space of 2.5 cm (1 inch).

Page Numbering: Page numbers should be included in each file by the submitter. Page numbering is not provided by POPS.

File Format: POPS accepts PDF and Microsoft Word file formats. PDF files are recommended.


Submissions should include the following required documents and may include several optional documents. No other documents will be reviewed. This set of information corresponds to what is currently requested by XRAC reviewers and largely to what is provided in current submissions, but it does expand the total permissible page count for many types of submissions. Many projects are not expected to use the full page-limit in all sections. Concise submissions are appreciated.

IMPORTANT: If page limits for the Main Document are exceeded, the Allocation Coordinator will return the submission without review.

Main Document: Required, 10 or 15 pages (5 pp. for Supplement Request). This document should have the scientific background, research objectives, and the justification of the request for all resources and resource types. The reviewers will focus on this document, and the document should include sufficient detail to permit reviewers to make a recommendation. As with a renewal research request, the Main Document is required, however, the previous year's Main Document can be re-used with updates to the computational plan and justification for the upcoming year's research. If there are changes to the scientific direction this should be addressed in the Main Document as well. The following page limits apply:

  • Single-Year Request for more than 10 million SUs: 15 pages.
  • All Other Requests: 10 pages.

Progress Report: Required for renewals and supplements, three pages. For renewal requests the reviewers also consider a PI's record of using their allocations and achieving meaningful results. This should be submitted as a separate document. The reviewers will consider this document for rating the successful use of prior allocations.

Publications resulting from XSEDE Support: Required for Renewals and Progress Reports, no page limit. This document should contain a listing only of bibliographic citations for reviewed publications that benefitted from access to XSEDE resources. These publications, authored by the PI or users of the allocation, may be in preparation, submitted, accepted, or published. This information is separated for XSEDE metrics purposes and should not include citations for literature cited elsewhere in the submission (see "References and Figures" below).

CVs: Required, no limit. This is a single document that includes CVs for the PI and all co-PIs. The two-page NSF or NIH format is highly recommended. For supplement or justification (rebuttals) submissions for which CVs for the same PI and co-PIs have already been submitted in the original request, this document can be omitted.

Special Requirements: Optional, 1 page. This document should be included if the completion of the research plan requires capabilities that fall outside an RP's standard user and usage environment. For example, jobs longer than the standard queue lengths, specific scheduling demands, or dedicated file system space. The XRAC is not required to read this document; the intended audience is the staff at the relevant RP(s).

Code Performance and Scaling: Required, 5 pages. This document can contain information to support claims of code performance and scaling that does not fit within the Main Document. Reviewers should not be required to closely scrutinize this document to evaluate the overall request.

References: Optional, no limit. A PI may separate a lengthy bibliography (for literature cited in the Main Document) in order to take full advantage of the maximum page limits. Please note that this bibliography is different from the "Publications Resulting from XSEDE Support" described above.


na = not applicable

PAGE LIMITS 10 pp.; 15 pp. for >10 million SU requests (see below for exceptions) 3 pp. no limit 2 pp.-format per CV; single combined document 1 p. 5 pp. no page limit
NEW Required na na Required Optional Required Optional
RENEWAL Required Required Required Required Optional Required Optional
SUPPLEMENT Required5pp. max. Required na Not required if no change in PI/CoPIs Optional Required Optional
JUSTIFICATION Required na na Not required if no change in PI/CoPIs Optional Required Optional
PROGRESS REPORT Progress Report is submitted as the Main Document to continue a multi-year allocation na Required Required Optional Required Optional
EXTENSION na na na na na na na
TRANSFER na na na na na na na
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Research requests are reviewed quarterly by the XSEDE Resource Allocations Committee (XRAC). The XRAC consist of volunteer experts from the faculty and staff of U.S. universities, laboratories, and other research institutions. All committee members have expertise in at least one area of computational science or engineering and serve a term of approximately three years.

The XRAC will ensure that:

  • All requests for resources that exceed a threshold level determined by XSEDE shall be peer-reviewed.
  • Written reviews of the resource requests shall be completed in a timely way and made available to the requestors and the allocation coordinators.
  • Recommendations to XSEDE for the allocation of resources based on the requests, reviews, and the available resources shall be developed and documented.
  • The environment for this process shall be consistent with the conflict-of-interest policy and shall maintain confidentiality of requestors and their reviews.

For details on the selection of XRAC members and the XRAC review and meeting process, please refer to the XRAC Policies and Procedures web page or email the help desk at


Each XRAC Research Request (New/Renewal/Supplement/Appeal) is reviewed by members of the XSEDE Allocations Committee (XRAC). The reviewers evaluate the merits of the proposal, based on the criteria of Section 7.2. When peer-reviewed funding information that supports the Computational Research Plan is provided, the science is not re-reviewed. Only when funding information is not supplied is the science reviewed. Each quarter requests are assigned to reviewers. After a period of one month to complete the reviews, the reviewers convene at a XRAC meeting to determine a Recommended Allocation for each XRAC Research Request (and any large Supplement or Justification). A preliminary discussion among the review team for each request is held to derive a Consensus Allocation for each request. Panel Discussions, including all reviewers, are held to evaluate each team's review summary in an open forum. Special considerations are noted. After a discussion, a Recommended Allocation for each request is arrived at by consensus.

After the Panel Discussion of the XRAC meeting, the total Recommended Allocation is determined and compared to the total Available Allocation across all resources. When the total Recommended Allocation exceeds the total Available Allocation and the ratio is close to 1, the committee is asked to reconsider requests for adjustment. When the ratio of total Recommended to Available Allocations is large, then there is a reconciliation process that uniformly adjusts all Recommended Allocations to remove oversubscription (i.e., all Recommended Allocations are reduced until the total is equal to the total Available Allocations). All requests are reduced by a global fraction that is adjusted for funding and the number of SUs requested (size). There are three weighting factors included in the adjustment. Any exceptions recommended by the committed are dealt with separately and on a case-by-case basis.

NSF supported Computational Research Plans have priority over all non-NSF supported components. In the (usual) case where both non-NSF and NSF funding are involved, the Recommended Allocation is split into NSF and non-NSF portions* (determined by the fraction of NSF and non-NSF support for these two categories). The non-NSF portion of a Recommended Allocation is reduced by the global faction times an additional factor (greater than 1). Also, there is a linear scale that reduces large requests more than small requests (requests below a certain cut-off have no additional reduction, while the largest request has the highest additional reduction).

* All funding used to support the Computational Research Plan of a XRAC Research Request must be reported in the Supporting Grants form in the POPS submission . Reviewers use this information to assess whether the PI has enough support to accomplish the Computation Research Plan, analyze data, prepare publications, etc. This assessment is blind to the type of funding support. For Reconciliation, Funding information is used to provide priority to the NSF funding portion of a request.


Every effort is made to avoid conflicts of interest. XRAC members are not allowed to review or be present for the discussion of requests from their home institution; former students, postdocs, or advisors; or current and recent collaborators. In addition, XRAC members who are also PIs or co-PIs on XSEDE resource requests do not review requests or participate in XRAC deliberations for the meeting to which they submit their requests.

If in the opinion of a PI, a certain individual has a conflict of interest, the PI may request that the individual not act as reviewer on their request or potential subsequent appeal. The Allocations Coordinator will consider such requests for the particular review. Such a request should be included as part of a PI's resource request submission in the Special Requirements document. (POPS will be modified to accept these names directly in the near future.)

The full XRAC conflict of interest policy is at [URL forthcoming] and is incorporated by reference into this document.


PIs will be notified of the results of the review of Research requests via an email notification within three weeks following the XRAC meeting.


All XRAC reviews are considered confidential and are only made available to:

  • the PI and co-PIs of the submitted request;
  • members of the XRAC without a conflict of interest;
  • XRAC reviewers of appeals (justifications), supplement requests, progress reports, or subsequent renewals for continuing allocations; and
  • XSEDE allocations officers; and
  • NSF staff.

XRAC requests and documentation are generally considered confidential, with access limited to the same sets of individuals. However, the requests may be made available to XSEDE User Services or Advanced User Support staff to assist a research group or evaluate their needs for advanced support.

XSEDE allocation amounts and descriptive project information (PI name and institution, title, and abstract) are not considered to be confidential.


PIs who wish to appeal the recommendations of the XRAC may do so by submitting a Justification (Appeal). A Justification should be submitted via POPS within four weeks of the date when the PI is notified of the review results.

A Justification is also used to supply additional information or clarification requested by the reviewers in order to make a final recommendation. A PI may also use the Justification to specify, in the PI's opinion, why the reviews of the original request and the resulting allocation were incorrect or unfair. A Justification can be used only to supply requested information or to provide the rebuttal. It may not be used to re-submit a poor request. In the latter case, the PI should submit a revised request in the next submission period (comments in the Request Summary will indicate options available for a rejected request).

If possible, the XRAC members who reviewed the original proposal will consider the Justification (Appeal). Reviewers are expected to respond within two weeks; the Allocations Coordinator may make a determination as to any increase to be made to any initial allocation, if resources are available. If the resources to be allocated are not available on the requested resources, the allocation may be made on another resource. For large requests, at least one favorable review is required before the Allocations Coordinator may make an assessment for an allocation. Alternatively, the allocation may be made at the beginning of the next allocation cycle on the requested resource.

7. Preparing a Successful Request Document

On average, more than 70 percent of Research requests receive allocations. However, some allocations may be for less than the level requested. To help ensure that you receive the allocation needed for you to successfully complete your research project, it is important that you provide an appropriate level of justification. The single most important review criterion is the justification of the resource request in the Main Document of the request. Inadequate justification for requested resources is often the reason for reduced or denied allocations. This section provides policies and guidelines to help you craft a successful submission.

In short, the bulk of the Main Document should focus on the resource request, whether for compute, storage, or advanced support.

  • For compute resources, the request should address the appropriateness of the computational methodology, the algorithmic capabilities that make this problem a good fit for the requested systems, and the rationale for the number of runs being proposed.
  • For storage resources, the request should address the appropriateness of the storage resource for the data sharing or management needs, the planned use and usage patterns for the data to be stored, and the rationale for the amount of storage space requested.
  • A request for Extended Collaborative Support to enhance the effectiveness and productivity of work can accompany an application for resources at any level, or it can be submitted stand-alone as a Supplement to an active grant. It requires the Principal Investigator (PI) to answer five (5) questions in the Resource request section of POPS. This request will be reviewed, usually in conjunction with your XSEDE grant proposal. ECSS management will then assess whether there is also a good potential match with the experts available to collaborate with your team.

The Main Document of a request for resources will succinctly state the scientific impact of the research to be conducted, and the existing merit-reviewed supporting grants for the research should be listed in the POPS forms.

If the research has had independent review and has been deemed worthy of scientific support as demonstrated by current financial support from a national agency or foundation, the scientific merit and approach will not be subject to further review by the XRAC.

In those circumstances where independent merit-review has not resulted in current financial support from a national agency or foundation, the Allocations Coordinator will highlight this to the reviewers and the XRAC will review the scientific merit and approach of the proposed work. For ongoing computational activities, the XRAC will also consider the progress made using prior allocations, including the publication of peer-reviewed manuscripts and other communications within the community.


The Main Document of the resource request will be reviewed against three criteria, which apply across all types of resources, with the level of detail of the review rising with the size of the requested resources:

  1. Appropriateness of Methodology: For compute requests, the choice of applications, methods, algorithms and techniques to be employed to accomplish the stated scientific objectives should be reasonably described and motivated. For storage requests, the data usage, access methods, algorithms and techniques to be employed to accomplish the stated research objectives should be reasonably described and motivated. For shared collections, requestors should describe the public or community access methods to be provided.
  2. Appropriateness of Research Plan: The steps in the research plan should explain how the research objectives would be achieved. For compute resources, the proposed computations should encompass simulation parameters (step size, time scale, ensemble parameters, etc.) that are needed to obtain accurate and meaningful results, as well as the human resources that can be devoted to the task. The amount of resources requested should be derived from the methodology and the research plan. If there are serious concerns about the research plan, reviewers will document those concerns in their reviews, and the PI may choose to address those concerns in an Appeal.
  3. Efficient Use of Resources: The resources selected should be used as efficiently as is reasonably possible and in accordance with the recommended use guidelines of those resources. For computational resources, performance and parallel scaling data should be provided along with a discussion of optimization and/or parallelization work to be done to improve the applications. If the reviewers conclude that the request is more appropriate on XSEDE resources other than those requested, they may recommend an allocation on those other resources instead.

In considering these criteria, the XRAC recognizes that scientific productivity is the end goal. If adapting to less familiar but, in the view of the panel, better architectures or algorithms requires a significant learning curve for the proposer, with a concomitant interruption of scientific productivity, the XRAC may suggest the alternatives, but nevertheless grant the requested resources with the proposed architecture and methods. In exceptional cases, where the reviewers conclude "beyond a reasonable doubt" that the proposed methods are so inefficient that they amount to a waste of public resources, they should not approve the request until their concerns are addressed by the proposer. Reviewers should be encouraged to recommend extended collaborative support, even for those proposers who have not requested it, as part of their recommendations for addressing shortcomings. For storage resources, information on required performance and expected access patterns should be provided for all data and collections to be stored and used along with a discussion of work done or planned to improve the efficiency of the data use.


In addition, PIs should describe their local cyberinfrastructure resources and other non-XSEDE resources available to them.

Local Computing Environment: Requests should describe briefly the local (e.g., campus or lab) computing environment available to a research team and, most significantly, how XSEDE resources will provide capabilities beyond those of local resources or why the requested XSEDE resources are required in addition to those resources.

Other Supercomputer Resources: If a PI has access to other supercomputer resources or is logically expected to have such access, as with researchers who are affiliated with or are collaborating with other agencies with resource facilities, the document should describe why those resources are not available to the group or why the requested XSEDE resources are required in addition to those resources.


To assist PIs in writing their documents, examples of successful resource requests are available as models for others to follow.

With these samples, reviewers have expressed the view that these were excellent examples of how an allocation request should be presented. In particular, the reviewers noted that in each case:

  • The request summarizes the research in context of the current state-of-the-art, outlines the computational algorithms to be used, and relates these algorithms to the research subsections.
  • The reviewers were provided sufficient information but not overwhelmed by details.
  • Justification for the allocation request was clear and closely coupled to computational experiments or projects. As such, if the committee needed to reduce the original request, the reduction could have been done rationally with minimum disruption to the investigator.
  • Results from previous allocations were summarized and related to this request.

8. Further Details on Eligibility

A PI who applies for an XSEDE resource allocation must be a researcher or educator at a U.S. academic or non-profit research institution. A principal investigator (PI) may not be a high school, undergraduate, or graduate student (but see Section 8.1); a qualified advisor must serve in this capacity. A postdoc is eligible to serve as a PI. XSEDE welcomes allocation requests from throughout the science and engineering community. This section clarifies and makes explicit the eligibility rules that apply to specific classes of researchers and educators.


While in most cases, a graduate student is ineligible to be PI of an allocation request, an exception is made for NSF Graduate Student Fellows and Honorable Mention recipients. Recipients of these NSF awards can submit requests for Startup allocations for compute time, per arrangement with NSF. In the POPS Startup submission form a checkbox is provided for a person to identify him- or herself as a fellow/honorable mention recipient. Include a CV and supporting documentation (grant number or an award letter) as part of the request submission.


Research staff employed by federal agencies or non-NSF FFRDCs are eligible to apply for an XSEDE allocation if their agency or center does not typically provide research staff with access to non-XSEDE HPC resources of adequate scope for the planned research.


Allocation requests submitted on behalf of faculty members at the military service academies, including the U.S. Military Academy, the U.S. Naval Academy, the U.S. Air Force Academy, the U.S. Coast Guard Academy, the U.S. Naval Postgraduate School, and the Uniformed University of the Health Sciences, will be accepted on the same basis as requests from other academic institutions.


State educational offices or organizations and local school districts may submit allocation requests intended to broaden the impact, accelerate the pace, and increase the effectiveness of improvements in science, mathematics, and engineering education in both K-12 and post-secondary levels. A teacher or educator at an accredited public or private K-12 school is eligible to apply for an allocation as PI.


Independent museums, observatories, libraries, research laboratories, professional societies and similar organizations in the United States that are directly associated with educational or research activities are eligible.


Scientists, engineers or educators located within the U.S. may be eligible for support, even if the individual is not employed by or affiliated with an organization provided that

  • the project is sufficiently meritorious and otherwise complies with the conditions of any allocation request;
  • the requestor has demonstrated the capability to carry out the project.

Unaffiliated individuals should contact the XSEDE Help Desk before preparing a request for submission.


A PI on a request must be a researcher or educator employed at a U.S. institution. Allocation requests with "foreign components" may be made through a domestic PI (with a foreign Co-PI). A foreign component is defined as the performance of any part of the project outside the U.S. either by the PI or a researcher, or researchers employed by a foreign institution. XSEDE will not provide an allocation to a PI that does not have a substantive role in the project; that is the PI may not simply serve as a proxy for a foreign researcher.

Collaborative projects involving non-U.S. researchers are encouraged as long as they include substantive intellectual participation by the U.S. researchers. In joint research projects, foreign collaborators are eligible to make use of that allocation in a manner consistent with the request.

Allocations requests involving foreign collaborators will be evaluated using the standard review criteria.


U.S. commercial organizations, especially small businesses with strong capabilities in scientific or engineering research or education may apply for an allocation. The NSF XD Program is interested in supporting projects that couple industrial research resources and perspectives with those of universities; therefore, it especially welcomes requests from cooperative projects involving both universities and the private commercial sector. It is necessary for these projects to submit their work in an open forum, and make the work readily available to the public.

A Principal Investigator may declare a commercial organization as the "institution" supporting his open-science research. In this case open-science support means that the organization has funding or an agreement (MOU) with an open-science agency, or a component of an open-science agency (usually a University, national open-science agency such as NSF and NIH, national laboratory such as Sandia, Argonne National Lab, etc., or a national funding agency such as DOE, DoD, etc.), to do research that is guaranteed to be accessible and submitted to an open-scientific organization or journal for peer reviewed dissemination of the scientific results. Proposals that are not supported by collaborative open-science funding are generally not considered for review. A submission through a commercial "institution" is also subject to screening by the Allocations Working Group, consisting of site-representatives and the XD Allocations Coordinator.

In addition to supporting scientific research by commercial organizations under the terms described above using the normal XSEDE resource allocation process, many of the XSEDE sites have active industrial partnership programs, including funded access to resources without the restrictions associated with free allocations; for additional information see the XSEDE Industry Partnerships page.

Last update: September 28, 2013