CRI Cray Y-MP2

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Cray Y-MP2 supercomputer

Cray Research, Inc.
In use: July 16, 1991 - September 1, 1994
Production use
Peak teraflops: 0.00
Processors: 2.00
Clock speed: 0.17GHz
Memory (terabytes): 0.00TB

The Cray Y-MP2 arrived at NCAR in June 1991. The machine was called Castle after the 14,265-foot Castle Peak, following an NCAR tradition of naming computers for "fourteeners" in the Colorado Rockies.

The machine was the first supercomputer in North America dedicated totally to climate simulation. It was funded by the Model Evaluation Consortium for Climate Assessment (MECCA), a numerical laboratory hosted by SCD and devoted to modeling climate change due to greenhouse gases.  MECCA was established by the University Corporation for Atmospheric Research (UCAR) and the Electric Power Research Institute (EPRI, the R&D arm of the U.S. electric utility industry), headquartered in Palo Alto, California, in 1990. UCAR, EPRI, the National Science Foudation (NSF) were joined in an expanded Accelerated Computing Environment (ACE) initiative by other organizations from government, industry, and academia, representing U.S., Dutch, French, Italian, and Japanese interests.

Five days after Castle came online, it was running at more than 90% capacity. For NCAR, the new Y-MP meant twice the computing power available for climate research. For scientists around the world, it meant getting model results in months instead of years.

Castle had two central processing units, 16 million 64-bit words (128 megabytes) of central memory, an integrated Solid-State Storage Device (SSD) with 128 megabytes of fast-access memory. It also had an Input/Output Subsystem (IOS), a separate computer which handled all the input and out put data and connected the Y-MP2 to Cray disk storage units, other computers, networks, and the Mass Storage System. Castle ran Cray's UNICOS operating system.

From July 1991 through December 1993, SCD made 43,248 Y-MP CPU hours available to MECCA (98.7% of system availability). These projects generated and archived about 5.5 terabytes of model output, accessed over 40,000 files from SCD's Mass Store System, and generated over 100 animations via the SCD Visualization Laboratory.

Castle was funded by MECCA through December 1993, and SCD ran the system until September 1, 1994.