hw.em.eee_setting: Enable Energy Efficient Ethernet
hw.em.fc_setting: Flow control
hw.em.rx_process_limit: Maximum number of received packets to process at a time, -1 means unlimited
hw.em.enable_msix: Enable MSI-X interrupts
hw.em.sbp: Show bad packets in promiscuous mode
hw.em.smart_pwr_down: Set to true to leave smart power down enabled on newer adapters
hw.em.txd: Number of transmit descriptors per queue
hw.em.rxd: Number of receive descriptors per queue
hw.em.rx_abs_int_delay: Default receive interrupt delay limit in usecs
hw.em.tx_abs_int_delay: Default transmit interrupt delay limit in usecs
hw.em.rx_int_delay: Default receive interrupt delay in usecs
hw.em.tx_int_delay: Default transmit interrupt delay in usecs