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Alliance for Application Performance at Extreme Scale


NERSC has partnered with the Alliance for Computing at Extreme Scale (ACES) collaboration of Los Alamos National Laboratory (LANL) and Sandia National Laboratory (SNL) to form the Alliance for Application Performance at Extreme Scale (APEX).

The focus of the APEX collaboration is on Application Performance of High Performance Computers. and on meeting the mission needs of its partners and in pursuing Advanced Technology concepts. We expect to use Non-Recurring Engineering (NRE) to guide and improve system performance and productivity.


NERSC and ACES begun collaborating with the procurement and deployment of two very similar systems "Hopper" at NERSC, and "Cielo" at LANL, both Cray XE-6 systems in 2010. The partnership was formalized and strengthened with the Trinity/NERSC-8 project for the procurement of the "Trinity" system at LANL, and "Cori" system at NERSC. APEX builds on this shared history.


NERSC-8/Trinity Project

The first set of systems procured under the APEX collaboration were the "Cori" system at NERSC and the "Trinity" system for ACES. NERSC and ACES partnered to release a joint Request for Proposal (RFP) for two next generation systems, NERSC-8 and Trinity, to be delivered in the 2015/2016 time frame.  The intent was to choose a single vendor to deliver two systems of similar technology.  This collaboration resulted in the procurement of two Cray-XC systems, one sited at LANL and one at NERSC. Details on the Cori system at NERSC are here.

NERSC-9/Crossroads Project

The current project of the APEX collaboration is the NERSC-9/Crossroads project. As before NERSC and ACES expect to release a joint RFP for two next generation systems, NERSC-9 and Crossroads, to be delivered in the 2020 time frame. More information on the NERSC-9/Crossroads project is available here.

The NERSC-9/Crossroads RFP is here.

Further information on the APEX benchmarks and workflows can be found here.



September, 2016: FAQs for the NERSC-9 RFP Technical specifications and Facilities requirements are published on the APEX website.

Mar 17, 2016: A new version of the workflows whitepaper has been released.

Nov 2, 2015: A draft of the APEX 2020 technical specification is currently available at APEX website. Please contact the APEX representatives for details. 

For any further information about the project, please contact the NERSC-9/Crossroads team:

NERSC-9/Crossroads Project Team