Personally, and others might agree the longer on the yeast and longer you age it the better it will be. This goes for most beers, but especially for high gravity and/or extra roasty beers. Both fit the bill of a robust porter.
If it were me I would primary 4 weeks. rack to a keg or seconday and crash cool for 1-2weeks. then Force carb and serve.
If you're bottle conditioning I would primary 4 weeks, prime and bottle for 4 weeks then chill for 1-2 weeks before serving...
Again longer is better...
Originally Posted by david_42
only the $500,000 strippers can handle the load.
<Insert list of brews planned, fermenting, or being consumed here>