The best replacement for infiniband is ethernet.

The best alternatives to infiniband are rated as following:
★★★★★  ethernet
★★★  fibre channel
★★  fcoe
★★  10gb
★  10g ethernet
★  10gbe
★  ethernet latency
★  roce
★  10ge
★  iscsi
  rapidio
  pcie
  10g
  myrinet
  10 gig ethernet
  10gb ethernet
  gigabit ethernet
  fiber channel
  iwarp

Your alternative for infiniband is not listed? Suggest!
Speaking about infiniband, one probably shouldn't forget about openmpi.

Other search terms related to infiniband and their ratings are:
★★★★★ openmpi
★★★ mpich2
★★ oracle rac
You have in mind a companion for infiniband and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of infiniband in all years. Click on graph for more.
infiniband
ethernet
fibre channel