These HCAs are not CX4 to QSFP the wiser

They utilise copper or optical CX4 to QSFP and XFP interfaces and are terminated at the server side on Host Channel Adapters (HCA in Infiniband parlance and yes each connected server needs an HCA).CX4 to QSFP from the HCAs in your servers to the Xsigo director and that is about as much Copper SFP+ copper cables are slighly higher priced than the equivalent CX4, but can only go 5ms.  That means you have to go to Optical quicker.  The Cisco list price of an SFP+ Optical tranceiver is $1795 (that is for 1 end…you need 2 to make a cable).  CX-4 optical is <$1000 list for teh entire active optical cable.  QDR (40Gb ) IB is already out and uses CX4 to QSFP…….and so will 40 GbE in a few years….so IB is actually paving the way for 40GbE. computing (HPC) and Data Center Solutions cable, including CAT6 Cable Kits Custom Rack Ready, SFP + cables, cables, CX4 40-Gigabit Ethernet QSFP + cable CX4 to QSFP splitter and a new cable line for external PCI Express x16 GPU-based personal supercomputers.