Confusion with Packet and Byte counters for RoCE over CX3

We are using RoCE over a CX3 (RHEL 6.4)

driver: mlx4_en

version: 2.1 (Apr  3 2013)

firmware-version: 2.11.500

We are confused by the RoCE packet and byte counters.  Eg,

    cat /sys/class/infiniband/mlx4_0/ports/1/counters_ext/port_xmit_packets_64

    cat /sys/class/infiniband/mlx4_0/ports/1/counters_ext/port_rcv_data_64

The packet counters seem be about a factor of 4 smaller...  Ie, if we multiple the number by 4, it seems to match the switch counters.  The byte counters have a larger multiplication factor.

Are we interpreting these counters correctly?

Thanks,

Dan