Pfsense -Hardware & Additional NIC card support for Gigabit connection



  • Hi All,

    I installed Pfsense 2.4.2 in DELL PowerEdge T20 server (Intel® Xeon® processor E3-1200 v3 product family & 12 GB RAM) as baremetal.
    For WAN interface I used built-in interface. For LAN interface I installed additional NIC ie, Intel PCI NIC.

    Main reason is, we are using this pfsense firewwall for Gigabit internet conection.

    While testing the Gigabit internet speed by connecting LAN cable directly from ISP device to my Laptop, I'm geting the speed around 985 Mbps download and 800 Mbps upload.

    After connecting Gigabit internet to my Dell T20 -Pfsense firewall's  WAN Interface. Then I checked the speed from its LAN interface I'm geting half of the speed ie, around 540 Mbps download & 710 Mbps upload.

    By Directly i'm getting the speed. but, from firewall i'm getting hardly half of the speed.

    Can anyone suggest me is this hardware DELL T20 & my Additional PCI NIC is compatible for pfsense & Gigabit connection.
    is that hardware or Additional PCI NIC, what causing the problem.



  • PCI as in actually PCI and not PCIe? PCI cannot support gigabit bandwidths.



  • In theory PCI is enough to support gigabit connection unless the bus speed is shared.



  • In theory it has enough bandwidth for half-duplex gigabit for one device on the bus. From what I read, if there are any old controller devices that use ISA, like a floppy controller, the ISA controller comes off of the PCI controller and cuts the PCI controller's bandwidth in half, down to 66MiB/s.

    This PDF has some interesting info https://pdfs.semanticscholar.org/6316/ad6b564201a5b860789cae3f43a7f132047f.pdf

    In short, PCI is TDMA and a single slow device can make the entire bus crazy slow and have very little effective bandwidth. It really depends on every little detail. But the theoretical maximum is half-duplex gigabit. Even worse is that PCI is itself half-duplex, which makes it more like wifi, where bi-directional traffic kills effective bandwidth.



  • @Harvy66:

    In theory it has enough bandwidth for half-duplex gigabit for one device on the bus. From what I read, if there are any old controller devices that use ISA, like a floppy controller, the ISA controller comes off of the PCI controller and cuts the PCI controller's bandwidth in half, down to 66MiB/s.

    This PDF has some interesting info https://pdfs.semanticscholar.org/6316/ad6b564201a5b860789cae3f43a7f132047f.pdf

    Fine, you win !!  :P


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