How long to cook Prime Rib

http://firecooker.com/recipes/entry/christmas-prime-rib/

I will be cooking mine at 220 till internal temp of 120.
pull off the egg and wait until it stops cooking out of the egg
raise to 500 degrees and back on for about 15 min to brown it good.
I saw Alton Brown do this on TV.
This might give you an idea. I think it will take longer. I'm going to cool one also. I dry aged mine a little over 21 days

I've got a six-pounder, and I'm going to use a combination of the suggestions here: some sort of rub, cook until 125 degrees, about 2 hours.

What's the Mad Max method?

If you like it medium-Rare, take it off at 115 and let it rest 10 minutes. At 125, if it rests it may get up to medium before you serve. on the time, at 350 it should take 1.5-2 hours. get a good sear on all sides then get you temp down and let the magic happen. i did one last weekend and it came out perfect. now they want me to cook them all the time.

merry christmas and good luck.
shannon

I have mine on right now. A 5 pounder 4 bone in. Its been on almost an hour and internal temp isnt even to 80 yet. Don't think I let it sit out of the fridge long enough. Hope its done for lunch, otherwise I'll tell 'em its for supper.