One of the world's leading technical institutes, the Tokyo Institute of Technology (Tokyo Tech) created the fastest supercomputer in Asia, and one of the largest outside of the United States. Using Sun x64 servers and data servers deployed in a grid architecture, Tokyo Tech built a cost-effective, flexible supercomputer that meets the demands of compute and data-intensive applications. Built in just 35 days, the TSUBAME grid includes hundreds of systems incorporating thousands of processor cores and terabytes of memory, and delivers 47.38 trillion floating-point operations per second (TeraFLOPS) of sustained LINPACK benchmark performance and 1.1 petabyte of storage to users running common off-the-shelf applications. Based on the deployment architecture, the grid is expected to reach 100 TeraFLOPS in the future. This article provides an overview of the Tokyo Tech grid, named TSUBAME. The first in a series of Sun BluePrints articles on the TSUBAME grid, this document discusses the requirements and overall system architecture of the grid, as well as the tuning performed to achieve high LINPACK benchmark performance results.