Does Console.WriteLine cause a performance penalty even when the console is not visible? (C#)

Question

I have a console application with lots of WriteLine() functions, this application should also run as a "service" (a scheduled task, the user is not logged in when it runs).

In this case, there is no actual cmd window to show. Will Console.WriteLine() still cause a noticeable performance penalty in such a case?

Answer 1

Yes it will cause performance penalty even when the console is not visible

my experiment was running this piece of code with the console visible and again with the console hidden and measure the performance

first run Console Visible 24683 Millisecond
second run Console Visible 23363 Millisecond

first run Console Hidden 167 Millisecond
second run Console Hidden 162 Millisecond

    static void Main(string[] args)
    {
        WriteMilionLines();
    }

    static void WriteMilionLines()
    {
        Stopwatch sw = new Stopwatch();
        sw.Start();

        for (int i = 0; i < 1000000; i++)
        {
           Console.WriteLine(i);
        }
        sw.Stop();

        string message = "ElapsedMilliseconds" + sw.ElapsedMilliseconds;
        File.WriteAllText(@"c:\log.txt", message);
    }

By commenting Console.WriteLine(i); line it will take Zero millisec

Answer 2

No, it won't be noticeable. Unless your application does 99% Console.WriteLine() and barely anything else, the difference will be negligible.

If you still worry about performance, you could wrap Console-Calls into a method that you have control over and measure the total time your application went through and even introduce a switch (bool variable) to control its calls.