New MacBook Pro, updated version of iTunes, using a LaCie 1TB drive for all of my music.

Why does iTunes perform the operation "Add To Library" so PAINFULLY slow? I will have music newly added to my iTunes folder and when I try and add it to the library, it takes sometimes 15-20 minutes to do so. On my other MacBook with the same drive, I could add an album in 15 seconds.

Something wrong with my hardware? Software?