[CentOS] 1U firewall hardware

> I would defiantly stick with PCIe for 5 NICs. Additionally Realtek
> NICs don't offer the best performance and their drivers are hit or
> miss. The Supermicro board has Intel PCIe NICs onboard and a PCIe
> expansion slot. This should give you full performance depending on the
> Atom processor. It really comes down to if you are just moving packets
> or needing to do packet inspection

The daughterboard I pointed to contains Intel 3 Gigabit chips.

By the way, the OP never told us what would be the intended use for the 
firewall he needs.