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.

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Patrick has been running STH since 2009 and covers a wide variety of SME, SMB, and SOHO IT topics. Patrick is a consultant in the technology industry and has worked with numerous large hardware and storage vendors in the Silicon Valley. The goal of STH is simply to help users find some information about server, storage and networking, building blocks. If you have any helpful information please feel free to post on the forums.


  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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