Cheap 10Gb SFP+ $19 Mellanox ConnectX-2 Cards

Mellanox ConnectX-2 EN
Mellanox ConnectX-2 EN

Recently Miniknight in the STH Forums found a great deal on Mellanox ConnectX-2 EN 10Gb SFP+ cards. The Mellanox ConnectX-2 EN cards are Ethernet only. That means that they will not work in Infiniband networks. They are also older cards and from Mellanox. Practically speaking, there are still a few examples of OSes without ConnectX-2 support. Prime examples are FreeBSD 9.3 based FreeNAS and NAS4Free versions which did not have built-in support for the cards. The bottom line is that in terms of compatibility, one does need to verify these cards will work.

Mellanox ConnectX-2 EN
Mellanox ConnectX-2 EN

Just to give one an idea, I do personally use these in my Windows 10 home workstation for a 10Gb SFP+ backhaul to my home network. Speeds are excellent.

One tip is that you can very inexpensively setup a network with a cheap fanless switch like the MikroTik CRS226 we reviewed recently and these Mellanox cards to provide a high bandwidth and low cost shared storage server/ VM set of ports to a network.

MikroTik CRS226 Front
MikroTik CRS226 Front

Here are some of the $19 or under listings for the cards used on ebay.

At under $19 each, adding low cost 10Gb Ethernet to networks can be done very cost effectively. There are now quite a few switch options (including the CRS226 mentioned above) that can allow one to merge 1GbE networks with 10Gb SFP+ Ethernet.


  1. These are pretty hard to resist, to the point the card’s cost is barely half the consideration now.

    Fleabay has some 1/3/5m cables that are around $20 and fiberstore has optics as low as $16. Switches with more than a few uplink ports are still mostly stupid overpriced though, its weird that 40Gbit IB switches are cheaper.

  2. {10Gb SFP+ backhaul to my home network} What do you mean back haul?

    I have an HP ProCurve 24-port GigE Managed Switch and CAT6 cabling in the home.
    Would these cards make any sense/ value for me?

  3. thanks for the tip- i had been paying $50 apiece for connectx-en cards / MT26448
    now i have enough to put 10G cards in everything and the 1G sfps i bought are for naught.


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