Titan (supercomputer)

Titan (supercomputer)
Name	Titan
Location	Oak Ridge National Laboratory
Manufacturer	Cray Inc.
Purpose	Scientific research
Active	2012–2019
Speed	27 petaFLOPS (peak)
Memory	710 terabytes
Storage	40 petabytes
Os	Cray Linux Environment
Power	8.2 MW

Titan (supercomputer). Titan was a Cray supercomputer that operated at the Oak Ridge National Laboratory (ORNL) in Tennessee, part of the United States Department of Energy's network of scientific computing facilities. It was the successor to the Jaguar system and, upon its debut in 2012, was one of the world's most powerful computers, designed to tackle grand-challenge problems in fields like climate science, nuclear reactor modeling, and materials science. Titan represented a significant architectural shift by combining traditional CPUs with energy-efficient GPUs to achieve extreme performance.

Overview

Titan was installed at the Oak Ridge Leadership Computing Facility (OLCF), a user facility dedicated to open science. The system was funded primarily by the DOE's Office of Science and served researchers from academia, government laboratories like Lawrence Livermore National Laboratory, and industry. Its primary mission was to enable simulations of unprecedented scale and fidelity, supporting the INCITE program which allocates time to projects with high potential for scientific breakthroughs. As a national resource, Titan played a crucial role in maintaining U.S. competitiveness in high-performance computing against international efforts in China, Japan, and the European Union.

Hardware and architecture

Titan was based on a Cray XK7 architecture, comprising 18,688 compute nodes. Each node paired an AMD Opteron 6274 16-core CPU with an NVIDIA Tesla K20X GPU, leveraging the CUDA parallel computing platform. This hybrid design aimed to deliver high floating-point performance while managing power consumption, a critical constraint for exascale computing research. The system utilized Cray Gemini interconnect technology for high-speed node communication and featured 710 terabytes of DDR3 memory. Its Lustre parallel file system provided 40 petabytes of storage, managed by the Cray Linux Environment operating system.

Software and applications

Scientific applications on Titan were ported and optimized to exploit its hybrid CPU-GPU architecture. Major codes included the Community Earth System Model for climate projections, the Denovo code for nuclear reactor simulation, and the LAMMPS molecular dynamics package. The OLCF's staff provided extensive support for programming models like OpenACC, OpenMP, and MPI to help researchers adapt their software. System software was built around the Cray Linux Environment, with job scheduling managed by the Moab Workload Manager and TORQUE resource manager, facilitating large-scale simulations across thousands of nodes.

Performance and rankings

In the November 2012 list of the TOP500, Titan achieved 17.59 petaFLOPS on the LINPACK benchmarks, claiming the number one position and surpassing the previous leader, IBM's Sequoia at Lawrence Livermore National Laboratory. Its theoretical peak performance was 27 petaFLOPS. Titan also topped the Green500 list in November 2012, highlighting its computational efficiency. It consistently ranked within the top five of the TOP500 for several years until being surpassed by systems like Tianhe-2 in China and later by its successor at ORNL, Summit.

History and development

The development of Titan began as an upgrade to the existing Jaguar system, a Cray XT5 supercomputer also located at Oak Ridge National Laboratory. The upgrade project, initiated in 2011, involved replacing Jaguar's compute modules with the new Cray XK7 hybrid nodes while reusing much of the existing infrastructure, such as the cooling system. This approach provided a cost-effective path to a twentyfold increase in performance. Titan entered acceptance testing in 2012 and was officially unveiled in October of that year, entering full production for the INCITE program in early 2013.

Impact and legacy

Titan demonstrated the viability of hybrid CPU-GPU architectures for leading-edge scientific computing, influencing the design of subsequent systems worldwide, including its successor Summit and Sierra at Lawrence Livermore National Laboratory. Research conducted on Titan led to advances in understanding turbulence in combustion engines, the properties of exotic materials, and the effects of climate change. The system was decommissioned in August 2019, having served its full operational lifecycle. Its technological lessons directly informed the DOE's Exascale Computing Project aimed at delivering the next generation of supercomputers.

Category:Supercomputers Category:Cray supercomputers Category:Oak Ridge National Laboratory Category:2012 establishments in Tennessee