Atom C2550 and I354 Performance and Support Question



  • I apologize that my first post is a question…but that's usually how it begins I suppose!

    I am looking at a SuperMicro SYS-5018A-MLTN4 rack mount configured with 4GB of DDR3-1600 ECC Unbuffered in single channel mode. It has an Atom C2550 2.4GHz Quad Core and built in four port I354 gigabit NIC.

    I have two questions about this setup:

    Is the I354 fully supported yet? From what I could tell in searches it seems to be a mixed bag at the moment.

    I plan to use it as a core inter-VLAN router on a 2 gigabit-2 port LACP trunk that connects to our switches. It will also route and firewall out to the Internet via a third port although this connection is only 15Mbps. Is this hardware configuration capable of handling 2Gbps full-duplex VLAN routing? 95% of the time there won't be more than 100Mbps passing through but I am trying to accommodate backups and future growth.

    Thanks in advance for advice.



  • The i354 works fine on my SuperMicro board with a C2758.  I don't know why it wouldn't work on your system.  You should consider the 8-core though, the price difference is typically negligible.

    The answer to your question is at the moment, no, you'll probably need to wait for 2.2 where we get multi-threaded pf.  100Mbit/s is nothing though.  If you don't need to do any filtering you should consider a L3 switch for that task.



  • I thought about it but our organization has little money and doesn't think too much about IT because they were so used to getting stuff donated. Our switches are already going to be Dell 2848 smart switches which are only $610 or so each before volume discounts. I'm interested in a real server because I do want to use filtering on the BYOD network.

    Thanks for the info. I will probably go live with IPFire or vanilla FreeBSD and migrate to pfSense once 2.2 goes gold.



  • We are running quite a few A1SRi-2758F systems on 2.1.3 (they are using the i354 as well). One thing I have found is that you will need to do a bit of tuning to get the cards working great. I had some major slow-dows until I discovered this information. I was always maxing out the mbuf table and causing kernel panics. I followed the instructions here, but here is what you need to do:

    In /boot/loader.conf.local - Add the following (or create the file if it does not exist):

    kern.ipc.nmbclusters="131072"
    hw.igb.num_queues=1
    

    That will increase the amount of network memory buffers, and make the card use one queue instead of multiple queues, to reduce the strain on the system.



  • @Smokeshow:

    We are running quite a few A1SRi-2758F systems on 2.1.3 (they are using the i354 as well). One thing I have found is that you will need to do a bit of tuning to get the cards working great. I had some major slow-dows until I discovered this information. I was always maxing out the mbuf table and causing kernel panics. I followed the instructions here, but here is what you need to do:

    In /boot/loader.conf.local - Add the following (or create the file if it does not exist):

    kern.ipc.nmbclusters="131072"
    hw.igb.num_queues=1
    

    That will increase the amount of network memory buffers, and make the card use one queue instead of multiple queues, to reduce the strain on the system.

    Tuning for NICs isn't going to help this situation, though changes like the ones you mentioned (well, at least the first one) are necessary for any system with this many cores and NICs.

    The C2758 lacks the CPU power to do more than 1Gbit or so in a single thread.  That isn't going to change until pfSense 2.2 drops and is based on FreeBSD 10 with multi-threaded pf.  Gonzopancho posted a couple weeks back that they had also found a way to get 12% more out of pf which will help even more.