Cooking time. HELP PLEASE!

I’m cooking a 6 pound boneless prime rib roast at 130 degrees. Can anyone tell me the MINIMUM amount of time it should take to reach temperature?

How thick is it? You can work on a rule of thumb of 30 minutes per half inch of thickness to get to temperature equilibrium (core temperature at the same temperature as bath water).

This would be your absolute minimum amount of time.

From there you’d decide if you want to add further time for tenderness.