The NEC Express5800/1000 series

System parameters:

The Express5800 series is more or less a renaming of the earlier TX7 series. The structure of the system has stayed the same but instead of the former Itanium 2 processors the new machines are offered with the Montecito processors. It is another of the Itanium 2-based servers (see e.g. also the Bull NovaScale, the SGI Altix 4000, and the Hitachi BladeSymphony) which recently appeared on the market. The largest configuration presently offered is the 1320Xe with 32 1.6 GHz Montecito processors. NEC had already some experience with Itanium servers offering 16-processor Itanium 1 servers under the name AsuzA and the already mentioned TX7 systems. So, the Express5800 systems can be seen as a third generation.

Processors are housed in 4-processor cells that connect via a flat crossbar. The bandwidth of the crossbar links is 6.4 GB/s. Unfortunately the documentation does not mention the bandwidth of the links between processors and memory within a cell. Although NEC still calls the machines SMP systems they are in fact ccNUMA systems with a low NUMA factor. The documentation speaks about "near-uniform high speed memory access".

Unlike the other vendors that employ the Itanium processors, NEC offers its own compilers including an HPF compiler which is probably available for compatibility with the software for the NEC SX-8 because it is hardly useful on a shared-memory system like the Express5800. The software also includes MPI and OpenMP.

Like the other Japanese vendors, Fujitsu and Hitachi, NEC very much emphasizes the RAS features of the system, targeting mission-critical operating environments.