Hi!
If you test on Windows Platform, you must use SMB Direct with firmware 2.10.720.
QDR's throughput is real 32Gb.
But you can use that performance on SRP, MPI, SMB Direct only.
QDR HCA's performance is 10Gb only. (8/10 encording 8Gb real performance).
If you want 40Gb IPoIB performance, switch to FDR CX-3 HCA and etc.
Good luck!