At this moment, high performance computing is clearly focused on parallelization because electronics does not allow processors frequency increasing like two decades ago. The most extended solution is the commodity hardware interconnected with a high performance network. In fact, the idea is based on having the maximum number of cores per processor connected with an efficient network in terms of latency.

In our case, growing up significantly on processors number under desktop type nodes would involve a very difficult and almost impossible management of cabling, and a non-efficient and very expensive air conditioning system to reject the heat produced by the equipments. Both issues are better solved with rack type configuration.

Infiniband network has been selected, as it is the one which better solves the key aspect of the network interconnection between nodes with latencies of around 2.25 microseconds instead of latencies between 29 and 120 microseconds of Gigabit Ethernet type. The Infiniband network used has a capacity of 20 Gbits/s. This solution allows scaling the number of nodes significantly. In our particular case, four selves having each one 32 nodes of 1U high, can deploy 128 nodes which imply having 1024 cores all together.

The last important aspect in our HPC cluster second generation is the parallel file system called Lustre. This system of files allow unified capacities of several Petabytes (Pb), being highly scalable, and obtaining the optimal efficiency using a high performance hardware like DDN S2A9900 units with a useful maximum capacity of 1 Pb with 1200 disks of 1 terabyte (Tb), writing at 5.6 Gbytes/s. This unit has been acquired with 80 disks of 1 Tb, obtaining a storage capacity of 64 Tb and writing at 2.6 Gbytes/s.