"The Cray XT Jaguar system now boasts of 45,000 quad-core AMD Opteron processors, along with 362 terabytes of system memory and a 10-petabyte file system. Jaguar also now offers 362 terabytes per second of memory bandwidth and an I/O bandwidth of 284 gigabytes per second."The supercomputer belongs to the DOE and resides at their Oak Ridge National Laboratory. See their press release here.
The Washington Post also has an article (with picture!) here.