1 5-7 bone prime rib, small end, bone in. Mix together 2 tbsp. kosher salt, 2 tbsp. coarse black pepper, 1 tsp. garlic powder, 1 tsp. onion powder, 1 tsp. sugar. Rub roast with spice mixture making sure to cover complete roast including ends. Place a temperature probe into center of roast. Place in smoker preheated to 375 degrees. Smoke one hour then reduce heat to 325. Remove from smoker when internal temp reaches 130 degrees for rare, 135 for medium rare, 140 for medium, and 145 for well done. Tent with foil for thirty minutes. Remove rib bones by fileting them off in one piece. Save for good eating later. Cut roast into 1 inch slices.