Entity Framework 6 - Knowledge Base (KB)

When generating 1000s of Entity Framework instances, when should I use SaveChanges()? (For example, during an import)

I am running an import that will have 1000's of records on each run. Just looking for some confirmation on my assumptions:...Which of these makes the most sense:...Run ...SaveChanges()... every ...AddToClassName()... call....Run ...SaveChanges()... every...