在新线程上启动方法时使用async关键字是否有效率？

Question

I have a program that downloads alot of data from the internet and saves it to my local db using the Entity Framework. I have this sample code below. Is it more efficient for me to start the method on a new thread and also use the async keyword when it is saving the model data or is this less efficient.

static void Main(string[] args)
    {
        using (DBModel model = new DBModel())
        {
            model.Database.Connection.Open();

            Task task = Task.Factory.StartNew(() => downloadData(model));
            task.Wait();
        }

    }

public static async Task<string> downloadData(DBModel model)
    {
        // do something first
        await model.SaveChangesAsync();
    }

Answer 1

Is it more efficient...

That's the wrong question. It's better to first consider which is more correct , and then search for more efficient methods once you have a proven performance problem in production code.

async methods should be used when doing operations that are naturally asynchronous. This includes any kind of I/O, such as downloading data from the Internet and EF.

Multithreading should be used if you want to free up the current thread when doing operations that are CPU-bound. You can use Task.Run (not StartNew , please ) to push work off to a background thread.

In your situation, just using async / await is more correct.