If they were not bound to the driver, do they show up in lspci output?
# lspci|grep -i mell
b0:00.0 Network controller: Mellanox Technologies MT27500 Family [ConnectX-3]
b0:00.1 Network controller: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function]
b0:00.2 Network controller: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function]