Infiniband for HPC

Which is the minimum hardware for InfiniBand for HPC ?

–  InfiniBand Adapter Card, Single-Port QSFP QDR IB (40Gb/s)  ($495 ~ R$ 4000)
–  Mellanox Passive Copper Cable, IB QDR/FDR10, 40Gb/s, QSFP, ($134 ~R$1200)
– Switch QDR 36-Port Managed InfiniBand ($10000 ~ R$50000)

For 10 computer nodes 10 x $495 (adpter card) + 10 x $134 Copper Cable + $10000 (switch) = $16290  ~ R$102000

For software, RocksCluster is very suitably solution.