I'm serving around 20 people this christmas so I've preordered two 5-rib roasts. I was wondering if its ok to stick both of these ribs in the same oven and cook them at the same time, as long as I follow the 20 minutes per pound rule? Will cooking two prime rib roasts side by side affect the cooking time in anyway? Let me know guys, i don't want to screw up the meat. Prime rib is toooo expensive to screw up.