What is a Burst Buffer?
The burst buffer is an intermediate, high-speed layer of storage that is positioned between the application and the parallel file system (PFS), absorbing the bulk data produced by the application at a rate a hundred times higher than the PFS, while seamlessly draining the data to the PFS in the background. Consequently, the burst buffer will be able to expedite the rate of I/O, allowing the application to return to performing computation sooner. The burst buffer is built from non-volatile memory devices that have several desirable properties such as high I/O throughput, low access latency, and higher reliability.
What is NVLINK?
The GPUs in Titan are connected today to the CPUs through a PCI Express (PCIe) interface, which limits how fast the GPU’s can access the CPU memory system. Summit will have a new high-bandwidth interconnect from NVIDIA, called NVLINK, and it will dramatically improve accelerated software application performance. With NVLink, the data moves between the CPU memory and GPU memory 5-12 times faster than PCIe, making GPU-accelerated applications run much faster on Summit.
How does the Unified Memory Feature help?
The faster data movement that comes with the NVLink, coupled with another feature known as Unified Memory, will simplify GPU accelerator programming. Unified Memory allows the programmer to treat the CPU and GPU memories as one block of memory. The programmer can operate on the data without worrying about whether it resides in the CPU’s or GPU’s memory.
What compilers will be available on Summit?
PGI, GCC, XL, LLVM
What performance tools will be available on Summit?
VAMPIR, TAU, HPC Toolkit (IBM), nvprof, gprof, Open|SpeedShop, and HPCToolkit (Rice)
What debugging tools will be available on Summit?
DDT, cuda-gdb, cuda-memcheck, Valgrind, stack trace analysis tool (STAT), pdb
What is Center for Accelerated Application Readiness (CAAR)?
The OLCF has created the Center for Accelerated Application Readiness, or CAAR, to help prepare codes for future generation systems. CAAR will establish eight partnership teams to prepare scientific applications for highly effective use on Summit. The partnership teams, consisting of the core developers of the application and staff from the OLCF, will receive support from the IBM/NVIDIA Center of Excellence at Oak Ridge National Laboratory, and have access to multiple computational resources. For more information about CAAR, please visit CAAR: Call for Proposals.
How much power will Summit consume? How does this compare to Titan?
We expect the peak power consumption of Summit to be 10 MW or less which is about 10% higher than Titan for 5 times the performance.
When will users get general access to Summit?
The plan of record is to provide general access for users to Summit in calendar year 2018.
When will Titan be retired?
The plan of record is to keep Titan available for users for a period of time after Summit enters production.
What is CORAL?
CORAL is the collaboration between the two DOE Office of Science Leadership Computing Facility centers, Oak Ridge Leadership Computing Facility (OLCF) and Argonne Leadership Computing Facility (ALCF), and the NNSA Laboratory, Lawrence Livermore National Laboratory (LLNL) to procure leadership computer systems for their respective sites in the 2017 timeframe. CORAL is an acronym for Collaboration of Oak Ridge, Argonne, and Livermore. For more information about CORAL, please visit
What does ‘Leadership Computing’ mean?
The DOE Office of Science provides a portfolio of national high-performance computing facilities housing some of the world’s most advanced supercomputers. These leadership computing facilities enable world-class research for significant advances in science.
The Oak Ridge Leadership Computing Facility (OLCF) was established at Oak Ridge National Laboratory in 2004 with the mission of accelerating scientific discovery and engineering progress by providing outstanding computing and data management resources to high-priority research and development projects.