Hi, schoondoggy.   Firmware version is 3.460.115-6465. Yes, megaraids should support uefi since SAS-1 series from 2011:     But I ran into another problem: overheat. Microserver has very tight layout, so without additional fan for 9271-4i temperatures going over 110 °C (images attached with external fan and without).   Still thinking what to do next.