The ixgbe driver has 8 RX queues by default. The multiple RX queues result in reduced driver performance in the promiscuous mode when compared to a single RX queue in the Solaris 10 10/08 and Solaris 10 5/09 releases. Multiple RX queues create kernel contentions. These kernel contentions might contribute to poor ixgbe performance in the Solaris 10 10/09 release.
Workaround: Set the ixgbe RX and TX queue values to 1. Perform the following steps:
Edit the /kernel/drv/ixgbe.conf configuration file.
rx_queue_number = 1; tx_queue_number = 1;
Reboot the system.