importing single images takes longer than importing hundreds

Why Does importing a single image take so much longer than importing many? Am I the only one?  I can import hundreds of photos per minute when importing a large selection, but when I try to import a single image I'm looking at 5-10 min wait times. I import from a solid state drive with embedded and side car previews. This has been a problem for the last couple of years but is starting to drive me crazy. Anyone else have this issue?