Introduction
Although old, Mellanox ConnectX-3 has been a good card with decent performance and a good price on second-hand markets. This makes it the straightforward choice for a high-performance home or lab network. (If you intend to run InfiniBand on ESXi 7.0 or higher, go for CX4.) Sometimes you would find a card with a strange firmware or one not compatible with your existent gear. Luckily you can change the port configuration on all CX3 cards with a simple firmware flash. Here’s how.