Not sure why you posted this in the storage forum, but typically a quad port card is just two dual port controllers on one physical card.   On the PCI bus you see what appears to be four (or two on dual port card)  individual network cards.  Even though there are two ports on one chip. I.e. # lspci | grep Broadcom 02:00.0 PCI bridge: Broadcom EPB PCI-Express to PCI-X Bridge (rev c3) 03:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet (rev 12) 06:00.0 PCI bridge: Broadcom EPB PCI-Express to PCI-X Bridge (rev c3) 07:00.0 Ethernet controller: Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet (rev 12)
When I look at the Broadcom page for NIC drivers for the NetXtreme II 5709, the NIC that they refer to is dual-port, not quad-port. Is that driver compatible with the quad-port version? In which case, I'll get the latest version of that driver installed
Broadcom NetXtreme II 5709 quad-port NIC Driver