A history nerd and an artist are visiting the museum. How much time will they need? Ballpark? I know this question is subjective.
Have you been to Pompeii, or will you visit Pompeii? How much time did you / will you spend there? Because a lot of the items at the museum came from Pompeii, seeing the old city ruins first helps set the context for what you see in the museum.
How much time do you normally spend in museums? I am not a museum person per se and still spent a few hours there.
I usually spend about three hours at this museum.
Should one visit the museum first or Pompeii Scavi first?
I have not been to the museum, but have been to the site.
I think doing the site 1st, would be the better way. That way when you see he actual artifact you know what/how it fit its space.
I would visit the Archaeological Museum first as it holds many original artifacts from Pompeii. Then go to Pompeii. I spent 3 hours there in early April. The next day took the train to Pompeii. You could easily spend half a day at Pompeii. Go early as people from the cruise ships swarm the place later in the morning.
My first visit was nearly 6 hours. The second was about 4, including 15-20 min. watching the astronomical clock, but also skipping some rooms.
IMHO it is unimportant which place you go first. Many naive visitors to Pompeii believe that the replicas placed there (for example, the faun and the Alexander mosaic) are the originals. Don't skip the Farnese Marbles in Naples. Because the Pompeii section of the museum is crowded in season, two hours is the minimum.
We did Pompei in March 2015 and then the Naples Archeological Museum in March of this year. It's not really necessary to do one before the other, but the ruins definitely make one gain perspective and appreciate the fabulous collection of pre-79 A.D. art at the Museum--it is absolutely incredible.
Spent about 3+ hours there, much of it in the Pompei exhibit. As Tim says, I regret not going to the Farnese wing--next trip for sure. It's really one of great museums in Europe.