How many minutes per pound should you cook prime rib?

I like to sear the surface of a rib roast a bit, to hold in the juices. I preheat the oven to HOT (~650ºF), put the roast in the oven and immediately turn down the thermostat to 325ºF. The oven temperature will drift down to the desired temperature. Start your timer as soon as you put the meat in, and roast for about 15 minutes per pound, and then start checking the meat's internal temperature. USE a MEAT THERMOMETER!