Hi. My name is Mariano from island Sicily / Italy.
The my Mac Pro 5.1 starts with some fans at maximum. Precisely:
1) power supply fan
2) expansion fan
3) front fan of the tray
4) rear fan of the tray
It is not possible to slow them down with the various fan adjustment tools, as it is an error in the internal temperature of the CPU that immediately exceeds 70 C.
Thanks for your help.