The first version of the draft technical specifications for Crossroads were released on November 1st 2015 to the vendor community for comment. Crossroads, one of two platforms targeted for delivery in 2020, will be the NNSA’s third Advanced Technology System. Crossroads will be the second platform procured as part of the Alliance for Application Performance at EXtreme Scale (APEX), a collaboration between Sandia National Laboratories, Los Alamos National Laboratory and Lawrence Berkeley Laboratory. Crossroads will be the third Advanced Technology System (ATS) since the NNSA merged their advanced technology and capability computing platform acquisition strategies. The Crossroads platform must balance the need to satisfy the NNSA’s mission while advancing technology on the path to exascale.
To maximize the impact Crossroads will have on the path to exascale, the procurement process was started a full five years prior to the target date for platform delivery, versus two to three years in prior procurements. Initiating interactions with technology providers in this timeframe has allowed the DOE to influence architectural directions of hardware, currently in the design phase, that will be available in the 2020 timeframe. Previous procurements have begun too late to have this opportunity for influencing hardware designs. In addition, the ATS program includes a significant amount of funding for non-recurring engineering. This enables the DOE to invest in targeted technologies that will enhance the performance of existing NNSA mission simulation codes and allow investigation and evaluation of future programming models and performance aspects of evolving hardware architectures on the path to exascale. The APEX team has established unprecedented communication channels with a wide range of technology providers of components that will potentially be included in the selected platform. Numerous face-to-face and regular, often bi-weekly, teleconferences have and continue to be conducted.
To maximize the impact of Crossroads, a different approach has been used in authoring the technical requirements. Due to the advanced nature of the procurement, the requirements are much less proscriptive than previous specifications. Part of the motivation for this approach is simply that many aspects of a system five years from now are impossible to accurately characterize. More importantly, the APEX design team wanted to leave as much room for technology innovation as possible in the process. As part of this change in procedure, APEX has released a document that describes NNSA and Office of Science workflows, basically how we use these massive resources. Through this document we are communicating with the vendor our mission, what we want to do, so that the vendor can construct a response using their technology that they feel will best achieve our goals. This document also provides a conduit for conversation that we are confident will also lead to the best possible platform in the 2020 time frame. Additional focus areas have been added to the technical specifications with the goal of taking advantage of emerging advanced technologies that the potential to positively impact platform efficiency.
