IBM POWER5 Integration into Production Environment

The chart shows the relative performance improvement of important NCAR applications on bluevista from the introduction of AIX 5.3 (red bars) only, and from AIX 5.3 plus Simultaneous Multi-Threading (SMT) (yellow bars). Reference code performance (blue bars) is defined as 1.0. AIX 5.3 plus SMT produced a significant performance improvement to these important NCAR applications, and this improved almost all other codes as well.

At the beginning of FY 2006, CISL deployed the hardware acquired with the final option of the Advanced Research Computer System (ARCS) contract with IBM. The new supercomputer bluevista is based on the IBM POWER5 processor and the High Performance Switch communication technology, and it offers the same computing capacity as NCAR's IBM POWER4 system bluesky. The deployment of bluevista effectively doubled the high-end computing resources available at NCAR. In addition, power and design improvements in the IBM POWER5 architecture halved the turnaround time for most applications. The deployment of bluevista was consistent with the SCD Strategic Plan (3.3 MB pdf file) to significantly enhance the high-end computational environment at NCAR during FY 2006, and it further complemented the production cyberinfrastructure available to the university, NCAR, and Climate Systems Laboratory (CSL) communities served by CISL.

During the first two months of bluevista availability, CISL provided priority access to the Nested Regional Climate Model project being conducted jointly by scientists in MMM and CGD. Access for this type of computing capability devoted to a grand challenge problem was unprecedented. It allowed scientists to simulate and analyze the large-scale climate of the Earth and the mesoscale processes that occur at the regional scale that may have significant impacts on the large-scale circulation. This is an important new area of investigation made possible by systems with this level of performance.

In June 2006, CISL system administrators and IBM support personnel upgraded the operating system of bluevista to AIX 5.3 and the compiler to the IBM XL version 10.1. The upgrades provided access to a feature of the IBM POWER5 architecture called Simultaneous Multi-Threading (SMT), which effectively allows the operating system to schedule two parallel threads to a set of parallel processors sharing the same memory. The result is an increase in application performance up to 30%, with little or no effort being required from the software engineer.

This computing resource supports the NCAR strategic priority of "Enhancing capability and capacity of NCAR supercomputing." NCAR's supercomputers are managed by CISL under the UCAR/NSF Cooperative Agreement and are supported by NSF Core funds including CSL funding.