Mellanox HCAs’ temperature threshold is 120 [degrees centigrade]. Temperature measured on HCA lower or equal than this threshold is considered as proper temperature.
You can measure it also using mget_temp tool that comes with MFT (Mellanox firmware tool) that can be downloaded from Mellanox website:
Where can I get a Mellanox document including this thermal specification?
I had the same question for the ConnectX-4 EDR (MCX455A-ECAT) cards. Any idea if the temperature threshold is 120 degrees C for that card?