[jamesfmilne]

I had always wanted to port Mellanox drivers to macOS to get away from paying through the nose for ATTO cards.

Great news that Apple have already done it!

Mellanox ConnectX 6 Lx is pretty cheap in comparison to ATTO.

[justinclift]

There are reasonably priced ConnectX-4's on Ebay these days too. :)

Random example (I don't know the seller): https://www.ebay.com/itm/166609931874

That's $39.99 for a dual port 25GbE card, and that generation are still on the official supported list for lots of things.