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Current Status: Retired

Carver was decommissioned on September 30, 2015. Please see Retirement Plans for more information.

Carver, named in honor of American scientist George Washington Carver, is an IBM iDataPlex cluster. Its unique features are nodes with relatively high  memory per core, a batch system that supports long running jobs, and a rich set of third party software applications. Carver also serves as the interactive host for various experimental "testbeds", including the Dirac GPU cluster and the Hadoop testbed.

Updates and Status

Current Status: [rest… Read More »

Getting Started

Learn the basics about running on the Carver system. This page will step you through logging in, compiling a simple test code, creating a batch script, submitting that batch script to the queue, monitoring your job in the queue and examining output. Read More »


Carver, a liquid-cooled IBM iDataPlex system, has 1202 compute nodes (9,984 processor cores). This represents a theoretical peak performance of 106.5 Teraflops/sec. All nodes are interconnected by 4X QDR InfiniBand technology, providing 32 Gb/s of point-to-point bandwidth for high-performance message passing and I/O. Read More »

User Environment

There are two primary ways that users can control their environment: CHOS and modules. Read More »


There are three compiler suites available on Carver: Portland Group (PGI), Intel, and GCC. The PGI compilers are the default. The MPI implementation on Carver is Open MPI, which is descended from LAM. In particular, note that Open MPI is not part of the MPICH family of MPI implementations. For each supported compiler suite, NERSC provides a version of Open MPI that is compatible with that compiler. Read More »

Running Jobs

Open MPI provides the orterun command to launch MPI applications. However, most people prefer to use one of two aliases: mpirun or mpiexec. Carver's batch system is based on the PBS model, implemented with the Moab scheduler and Torque resource manager. Read More »

File Storage

Carver has 3 kinds of file systems available to users: home directories, scratch directories and project directories, all provided by the NERSC Global File system. Read More »

Software and Tools

The table below shows the software installed on Carver that is managed by modules. Read More »

Retirement Plans

The Carver system was retired at the end of September, 2015. Carver users can migrate their workload to one of the other NERSC systems, primarily Edison. This page is provided to assist users in that migration. Schedule Carver's final day of operation was Wednesday, September 30, 2015. User logins, interactive processes, and batch jobs were terminated beginning at noon. The Global Scratch file system also became read-only on all other systems. Batch results may be recovered by logging in to any… Read More »