Hello,

actually, it's more complicated.

The Trace class uses TraceListeners to which it delegates the messages. By
default, the DefaultTraceListener is added, which writes to the Win32
OutputDebugString function.

But you can add other (Like textfiles via TextWriterTraceListener) or create
eventlog entries (EventLogTraceListener).

I personally use the TraceSources nowadays, because you can use them as
"categories" which can be enabled and disabled via app.config and you can
have more than one in your application.

When I write console applications, I don't use Console.Out anymore, but add
a TextWriterTraceListener(Console.Out) to the Listener collection...

Now, the costs depend on the number of listeners you have and the verbosity
configured via the app.config file. You'll really have to measure it...

Best regards,
Henning Krause