Yes, PCIE supports full duplex communication.
Yes, PCIE supports full duplex communication.
The ASRock ITX J4005 motherboard is scheduled to arrive today for a pfSense installation. It will connect to a PCIE enterprise NIC, which I plan to upgrade later as internet speeds improve. The device uses a PCIE slot that physically supports x16 but electrically only x2, corresponding to PCIe 2.0 standards offering up to 1000MB/s (8000Mbps). If a dual NIC PCIe controller is used for multi-gigabit performance, and I also consider SFP+ networking, the question is whether full duplex operation applies. In that case, the total bandwidth could reach 1000MB/s both in and out simultaneously. As a network interface, any data entering the WAN port must exit through the LAN port. If it isn’t fully duplex, the theoretical maximum speed for the pfSense box would be reduced to around 500MB/s or 4000Mbps.