Opteron-Based Supercomputer Aims At Petaflops Barrier

The Cray XT4 supercomputer, formally code named 'Hood', runs AMD's dual-core Opteron processors. It's designed, according to Cray, to upgrade to AMD's upcoming quad-core processors when the chip technology is released.

"While the theoretical peak speed of supercomputers may be good for bragging rights, it is not an accurate indicator of how the machine will perform when running actual research codes, which is what our 2,500 users are most interested in," said Horst Simon, director of the NERSC Division at Berkeley Lab, in a written statement. "To better gauge how well a system will meet the needs of our users, we developed SSP, a sustained system performance benchmark suite. Under this real-world performance test, the new Cray XT4 system will deliver over 16 teraflops on a sustained basis."

The Cray XT4 supercomputer uses as many as 30,000 dual-core Opteron processors, along with the Cray SeaStar2 interconnect chip to provide added scalability and performance, according to Cray. Unlike typical cluster architectures, in which many microprocessors share one communications interface, each Opteron processor in the Cray XT4 system is coupled with its own interconnect chip. Providing six links in three dimensions, the SeaStar2 chip uses its embedded routing capability to take advantage of HyperTransport technology and accelerate communications among the processors.

The system also uses single-socket processor nodes with local memory and direct interprocessor communications, as well as a low-jitter operating system. And the second-generation Cray SeaStar2 interconnect chip utilizes HyperTransport technology and built-in routers to boost bandwidth and reduce latency for data moving among processors or fetched from memory.

The Cray XT4 supercomputer is shipping now. Pricing was not disclosed.