When using Trusted_Connection=true and SQL Server authentication, will this affect performance?

Question

If a connection string specifies Trusted_Connection=true with SQL Server authentication mode, will performance of my web application be impacted?

Answer 1

This will probably have some performance costs when creating the connection but as connections are pooled, they are created only once and then reused, so it won't make any difference to your application. But as always: measure it.

---

UPDATE:

There are two authentication modes:

1. Windows Authentication mode (corresponding to a trusted connection). Clients need to be members of a domain.
2. SQL Server Authentication mode. Clients are sending username/password at each connection