Are you asking what is the max junction temp for the GPU? Around 110°C is where it will start to throttle or exhibit issues.
Or are you asking what temp an XFX RX 580 should be when gaming? Since board partners use different cooling solutions your card isn't directly comparable to a reference card or other makes/models, and different game loads will cause different temperatures also. So it depends.
Ryzen R7 5700X | B550 Gaming X | 2x16GB G.Skill 3600 | Radeon RX 7900XT
Ryzen R7 5700G | B550 Gaming X | 2x8GB G.Skill 4000 | Radeon Vega 8 IGP
Ryzen R5 5600 | B550 Gaming Edge | 4x8GB G.Skill 3600 | Radeon RX 6800XT