Question How do I undervolt an XFX Radeon RX 590 Fatboy ?

[M Uzair Arshad]

i have an XFX Radeon RX 590 Fatboy. Currently at 1545mhz core clock at 1150mV. it pulls around 185w at max in game while temperature goes to 74 C max. I have no issue with temperature but i want to bring down power consumption. I have tried multiple combinations for undervolting such as 1510mhz at 1030mV, 1520 at 1110mV. For the first one the power consumption was very good around 160w at max and it boosted fps as well.

These undervolts are stable in Superposition and Rise of the Tomb Raider benchmarks but they would crash in Arena Breakout Infinite and sometimes in Tomb Raider's benchmarks as well. I read somewhere that the
XFX Fatboy edition of the RX 590 cannot be undervolted. Can someone help me with the exact combination for undervolting, or tell me if it is even possible to undervolt the XFX Fatboy edition?