This IDC Buyer Case Study first presents an organizational overview of Texas Advanced Computing Center (TACC), including the size of the center and its available resources and objectives. We then focus on TACC's recent acquisition of Ranger, a near-petascale Sun Constellation System. IDC looks at how TACC and Sun have approached the challenges that have arisen on several fronts in deploying an HPC system capable of more than 500 teraflops for use in TACC's "open science" environment, which supports NSF and other researchers from across the country. IDC presents its findings to provide insight and best practice messages to those planning large or petascale HPC installations of their own.