If you start the server using minimal configuration, the tempdb is created at the default directory instead of the directory that it is configured to use. It will also create it as the size of the model database instead of the configured size. If you use the trace flag, tempdb won't be created at all. Notice that the trace flag 3609 is not supported and at most articles that explain this trace flag, you'll see the warning that this trace flag should be used only if Microsoft support team directed you to do it. In short - DON'T USE THE TRACE FLAG 3609.

Adi