Scale new heights. Discover new solutions.

Oak Ridge National Laboratory's next High Performance Supercomputer.

Coming 2018.

The Next Peak in HPC

Summit is the next leap in leadership-class computing systems for open science. With Summit we will be able to address, with greater complexity and higher fidelity, questions concerning who we are, our place on earth, and in our universe.

Summit will deliver more than five times the computational performance of Titan’s 18,688 nodes, using only approximately 4,600 nodes when it arrives in 2018. Like Titan, Summit will have a hybrid architecture, and each node will contain multiple IBM POWER9 CPUs and NVIDIA Volta GPUs all connected together with NVIDIA’s high-speed NVLink. Each node will have over half a terabyte of coherent memory (high bandwidth memory + DDR4) addressable by all CPUs and GPUs plus 800GB of non-volatile RAM that can be used as a burst buffer or as extended memory. To provide a high rate of I/O throughput, the nodes will be connected in a non-blocking fat-tree using a dual-rail Mellanox EDR InfiniBand interconnect.

Upon completion, Summit will allow researchers in all fields of science unprecedented access to solving some of the world’s most pressing challenges.

Summit Fact Sheet

Titan vs Summit

Compute System Comparison

Feature Titan Summit
Application Performance Baseline 5-10x Titan
Number of Nodes 18,688 ~4,600
Node performance 1.4 TF > 40 TF
Memory per Node 32 GB DDR3 + 6 GB GDDR5 512 GB DDR4 + HBM
NV memory per Node 0 1600 GB
Total System Memory 710 TB >10 PB DDR4 + HBM + Non-volatile
System Interconnect
(node injection bandwidth)
Gemini (6.4 GB/s) Dual Rail EDR-IB (23 GB/s)
Interconnect Topology 3d Torus Non-blocking Fat Tree
Processors 1 AMD Opteron™
1 NVIDIA Kepler™
6 NVIDIA Volta™
File System 32 PB, 1 TB/s, Lustre© 250 PB, 2.5 TB/s, GPFS™
Peak power consumption 9 MW 15 MW

Summit FAQs

"Summit, like Titan, will open a door to new ways to simulate and explore complex systems in the natural world. Our scientific community will see decreased time to solution, along with the ability to increase the complexity of their computational models, improving the simulation fidelity of a wide variety of important phenomena that are beyond the range of conventional experimental investigations."

— James J. Hack, Oak Ridge Leadership Computing Facility

Center for Accelerated Application Readiness

The OLCF has selected the next set of partnership projects into its Center for Accelerated Application Readiness (CAAR) program, a collaborative effort of application development teams and staff from the OLCF Scientific Computing group to prepare for Summit. These projects were chosen based on a computational and scientific review conducted by the OLCF in consultation with the ALCF, NERSC, IBM and NVIDIA. The application teams represent a broad range of computational algorithms and programming approaches in a diverse range of scientific disciplines including astrophysics, biophysics, chemistry, climate modeling, combustion engineering, materials science, nuclear physics, plasma physics and seismology.

CAAR Projects


  • CAAR Call for Proposals Opens CY2014 Q4
    Open call for proposals to collaborate with the OLCF to prepare scientific applications for Summit.
  • CAAR Proposal Review CY2015 Q1
    Review Proposals to select the 8 CAAR teams.
  • CAAR Workshops CY2015 Q2
    Workshops to help introduce CAAR teams to Summit
  • CAAR Application Readiness Phase I & II CY2015 Q2 – CY2017 Q2
    CAAR teams work to refactor and port code
  • Summit Monthly Screen Casts Begin CY2017 Q3
    Monthly online tutorials to introduce users to various aspects of Summit
  • Summit Webinars Begin CY2017 Q4
    Monthly webinars to prepare users to for Summit
  • Summit On-Site Workshops Begin CY2018 Q1
    On-site, hands-on workshops to prepare users for Summit
  • Summit General User Access Begins CY2018
    Target date for user access to Summit

Transitioning to Summit:
Preparing Titan Users for Fivefold Computing Power

Summit will provide revolutionary performance by way of evolutionary changes to the current Titan hybrid architecture, making Summit an ideal follow-on system to Titan. By developing and refactoring applications to improve performance portability on accelerated architectures, Titan users will be better positioned to take advantage of Summit, as well as other next-generation leadership computing resources, and beyond. Users can create applications that explore performance portability and exploit untapped parallelism by:

  1. Using accelerated programming libraries whenever possible
  2. Preferring high-level compiler directives such as Open MP/Open ACC over low-level frameworks such as CUDA or OpenCL
  3. Exposing as much node-level parallelism as possible
  4. Relying on a suite of development tools to maximize parallelism

The OLCF has established best practices for leadership-class computing for more than a decade. The OLCF created the Center for Accelerated Application Readiness, or CAAR, to help prepare codes for future generation systems. For Summit, CAAR will have a competition and select eight partnership teams to prepare their important scientific applications for highly effective use on Summit. The partnership teams, consisting of the core developers of the application and OLCF staff, will receive support from the IBM/NVIDIA Center of Excellence at ORNL and have access to multiple computational resources. For more information about CAAR, please visit CAAR: Call for Proposals.

Coinciding with the Summit launch, the OLCF will offer various tutorials, webinars, and workshops to help make sure users are ready on day one. During this three-year period of planning and development, please be aware that the OLCF’s goal is to smoothly transition from Titan to Summit by providing an abundance of guidance to users during the process.


Prior to the Summit launch, OLCF user assistance staff and vendor partners will host workshops to ensure users get the most out of Summit as well as the facility’s data and storage resources.


While users can still join us in person for Summit workshops, we will also provide them as webinars so users can plug in from anywhere in the world and refer to these resources at any time.


Users preparing applications for Summit will be able to access coding tutorials prior to the Summit launch that provide “how-to” examples of programming operations for an accelerated architecture.


Extensive details on the Summit system, including software installations, file systems, programming environment, and more will be available online as a Summit User Guide before Summit is operational.

Stay updated on these and other resources
available at the OLCF User Assistance Center

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