The computer runs native 32 and 64-bit codes. The XD1 is intended for sustained application performance and what the developer calls the direct-connected processor architecture, a way to link processors to each other and memory, eliminating interconnect bottlenecks. Each chassis holds up to six two-way symmetric multiprocessor (SMPs) for a total of 12 processors/chassis. This provides 30 times the bandwidth and lower latency than typical clusters. Main memory per chassis is 12 to 48-Gbytes PC3200 ECC SDRAM. Memory bandwidth is 12.8 Gbytes/sec/SMP. The computer also sports self-monitoring and selfhealing features to simplify system administration and ensure high availability. The XD1 is aimed at big jobs (hours and days) that need many processor and close processor interaction. Tests shows the XD1 message-passing method can send a 2-byte message before others can send their first byte. Prices: starting under $100,000.
Each chassis can hold 12 processors and 12 chassis per rack for a grand total of 691 Gflops peak theoretical performance with 2.4-GHz CPUs.
Direct Connected processor architecture in the XD1 maximizes message passing by directly linking processors to each other through a highperformance interconnect that eliminates sharedmemory contentions and PCI bus bottlenecks.
Cray Inc.,
411 First Ave. S, Suite 600, Seattle, WA 98104,
(206) 701-2000, cray.com