CRI Cray T3D

The NCAR CRAY T3D came online on July 1, 1994. It was a massively parallel processing (MPP) system that started out with 64 processors and had 128 after an upgrade in 1997.

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

The T3D had 1,024 megawords (8 gigabytes) of memory and a clock speed of 6.67 nanoseconds. It was tightly coupled to the CRAY C90 Antero, making Antero's resources – its I/O functionality, I/O subsystem, high-speed disks, HIPPI and FDDI network interfaces, and Mass Storage System connectivity – available directly to the T3D. Because the only I/O paths to it were from Antero, the T3D did not have its own system name.

The T3D ran the Cray UNICOS MAX operating system and supported Fortran 77, CRAFT (Cray Research Adaptive Fortran programming model), C, C++, and Assembler. It offered utilities such as 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 to it from Antero. It was suited to jobs appropriate for an MPP system — parallel applications that were distributed efficiently among the processors and kept all processors busy with useful work most of the time.

While NCAR discontinued maintenance on it in December 1998, the Scientific Computing Division operated the Cray T3D until June 1, 1999. It was removed from the NCAR Mesa Laboratory's machine room two days later to make room for Blackforest, an IBM SP RS/6000.