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.

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.

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.