Supercomputing at ORNL
XT5 Partition 6-Core Upgrade
Each processor in the XT5 partition’s compute pool has successfully been upgraded from 4-core to 6-core. The upgraded partition contains 224,256 compute cores.
Upgrade Status
The upgrade was completed on October 26
Please Note: The scheduling policy changes
Upgrade Schedule
The upgrade was performed in a rolling fashion, keeping a significant fraction of the XT5 available to the users for production science through most of the process.
The following table provides the upgrade schedule. More information on the upgrade can be found on the road map page.
Jaguar is the primary system in the ORNL Leadership Computing Facility (OLCF).
XT5 Partition
The XT5 partition contains 224,256 compute cores in addition to dedicated login/service nodes. Each compute node contains two hex-core AMD Opteron processors, 16GB memory, and a SeaStar 2+ router.
XT4 Partition
The XT4 partition contains 7,832 compute nodes in addition to dedicated login/service nodes. Each compute node contains a quad-core AMD Opteron 1354 (Budapest) processor running at 2.1 GHz, 8 GB of DDR2-800 memory (some nodes use DDR2-667 memory), and a SeaStar2 router. The resulting partition contains 31,328 processing cores, more than 62 TB of memory, over 600 TB of disk space, and a peak performance of 263 teraflop/s (263 trillion floating point operations per second).
The SeaStar2+ router (XT5 partition) has a peak bandwidth of 57.6GB/s, while the SeaStar2 router (XT4 partition) has a peak bandwidth of 45.6GB/s. The routers are connected in a 3D torus topology, which provides an interconnect with very high bandwidth, low latency, and extreme scalability.
The operating system for Jaguar is the Cray Linux Environment. This consists of a full-featured version of Linux on the service nodes and the Compute Node Linux micro-kernel on the compute nodes. The micro-kernel is designed to minimize partition overhead allowing scalable, low-latency global communications.


Michael E. Bartell, chief information officer at the Federal Deposit Insurance Corporation (FDIC) in Washington, D.C., has been named chief information officer (CIO) for the Oak Ridge National Laboratory. (
James J. Hack directs the National Center for Computational Sciences (NCCS) and the Oak Ridge Climate Change Science Institute. (
David C. Bader is the Deputy Director of the Oak Ridge Climate Change Science Institute, where he oversees of ORNL’s 2003 climate change research funded by the DOE Office of Science. (
Arthur Bernard Maccabe will direct the Computer Science and Mathematics (CSM) Division at Oak Ridge National Laboratory. (