CRI Cray T3D

Cray Computer Corporation
Clock Speed: 
Dates Used: 
Friday, July 1, 1994 to Tuesday, June 1, 1999
Microprocessor Peak Teraflops: 
Memory (terabytes): 
Number of Processors: 
Electrical Power Consumption: 
41.40 kW

The CRAY T3D at NCAR came online on July 19, 1994. It was a massively parallel processing (MPP) system that started out with 64 processors and was upgraded in 1997 to 128 processors.

The T3D was jointly funded by the High Performance Computing and Communications Program (HPCC) and the U.S. Global Change Research Program (USGRCP). Thus, the Climate Simulation Laboratory was responsible for the main usage of the T3D. However, some time was allocated on the T3D to projects that qualified as Grand Challenges under the HPCC program.

The T3D had 1,024 megawords of memory and a clock period of 6.67 nanoseconds. It was tightly coupled to the CRAY C90 (antero), making antero's resources (I/O functionality, I/O subsystem, high-speed disks, HIPPI and FDDI network interfaces, and Mass Storage System connectivity) directly available to the T3D. Because the only I/O paths to it were from antero, the T3D did not have its own node name.

The T3D ran the UNICOS MAX operating system and supported Fortran 77, CRAFT (Cray Research Adaptive Fortran programming model), C, C++, and AS (Assembler). It offered utilities such as PVM (Parallel Virtual Machine), the TotalView Debugger, and the Apprentice performance tool. It also offered the mathematical and scientific libraries libm.a and libsci.a for MPP use.

The T3D was accessed by logging in to antero or by submitting batch jobs. It was suited to jobs appropriate for an MPP system — i.e., parallel applications that were distributed among the processors efficiently and kept all processors busy with useful work most of the time.

The Cray T3D was officially decommissioned on December 11, 1998; it was operated without support until June 8, 1999, and removed from the machine room two days later to make room for the IBM SP RS/6000, blackforest.

Antero ran the UNICOS operating system, supported the Fortran 90, C, and C++ compilers, and offered many vendor-supplied utilities as well as mathematical and statistical software. The machine was suitable for long-running multitasked jobs, jobs with very large I/O requirements, and interactive and batch jobs requiring up to 48 megawords of memory.