Add vs AddRange in EF Core: The Performance Myth You Need to Stop Repeating

This article debunks a common performance myth in Entity Framework Core: that calling Add() in a loop is significantly slower than using AddRange() due to DetectChanges scans. It explains that this advice originated from Entity Framework 6, where DetectChanges ran on every Add() call, but EF Core (from its first release) handles change tracking differently, making the performance difference negligible. The post clarifies that AddRange() does not provide the claimed benefit in EF Core and warns against outdated advice still circulating online. It also notes that third-party tools like Entity Framework Extensions don't address a non-existent problem. Aimed at .NET developers, it encourages verifying performance claims and understanding EF Core internals.