[OMPI users] very low performance over infiniband

[Bob Lin]

Dear developers, I have met a rather weird problem . Our newly assembled 
cluster is using openmpi-1.6.3. When doing hpcc test, no err is reported 
, the network latency ,bandwith , are quite normal. but the GFlops which 
using HPL and MPIFFT is too low , just 2% of the theoretical value.

The system is quite normal ones:  Mellanox infiniband QDR switch , 
CentOS 6.2 with OFED-1.5.4

 Now the problem is there is no error reported , so I don't have any 
idea about what is wrong.