I am pretty sure my cards were the same way, voltaire but I had to re-flash them with the connectX firmware to get them to work with windows. You can try this:
Download the mellanox firmware tools, and do the following:
flint -d /dev/mst/mt4099_pci_cr0 query
you're looking for the "PSID" of the device, which will be listed as "board_id" Take that board ID and check mellanox's site for latest firmware. I am pretty sure they are some flavor of connectX, but I may be wrong.
As far as drivers, you have two choices. On the server 2008r2 server you can download and use the openfabrics drivers which should work, but they aren't compatible with 2012 yet. The 2012 server your best bet is to get the card flashed to the latest BIOS and download version 4.2 of the mellanox drivers and try those, they are the last version compatible with 2012 that support ConnectX cards. If they're Infinihost III cards, you're probably out of luck on the 2012 server until openfabrics releases a 2012 compatible driver (if ever)