This is the first installed system of the Cray, Inc. XT3 product line announced in October 2004. A team of Cray, Inc. engineers worked together with PSC and Westinghouse staff. “The modularity of this system,” says J. Ray Scott, PSC assistant director of systems and operations, “made it feasible for us to move expeditiously and to split the installation in this way.” Scott and his staff worked through the holidays to oversee the installation. A number of applications are running on the new system. These include storm forecasting, earthquake modeling, quantum chromodynamics, cosmology and numerical relativity. A quantum materials science application, LSMS, shows per-processor performance on the XT3 more than twice that of LeMieux, PSC’s existing Terascale Computer System. PSC manager of strategic applications, Nick Nystrom, and his staff have coordinated bringing these applications onto to the new system.