Hardware

Ekman is a distributed memory cluster consisting of 1268 compute nodes. Each node has two AMD Opteron 2374HE processors. Their ccNUMA architecture makes memory affinity important for optimal application performance. On Ekman this means that each CPU has 8 GB DDR2 RAM directly attached (for a total of 16GB RAM per node). While effects are mitigated by the cache hierarchy, directly attached memory is faster to access than memory attached to the other CPU.

Multi-CPU AMD Opteron systems in general (and Ekman-nodes in particular) are ccNUMA architectures making matters of memory affinity important for optimal application performance. On Ekman this means that each CPU has 8 GB DDR2 RAM directly attached (for a total of 16GB RAM per node). While effects are mitigated by the cache hierarchy, directly attached memory is faster to access than memory attached to the other CPU

Each CPU has 4 cores for a total of 8 cores per node. Cores can be considered independent compute units. However, it is important to realize that cores do share (and thus sometimes are competing for) finite resources, the most important being memory and interconnect bandwidth.

The interconnect is a full bisection bandwidth (FBB) Infiniband fabric with a multiple root tree structure. All links are 4xDDR making the per-link bandwidth 2GB/s.

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