SaveChanges vs SaveChangesAsync基准测试：奇怪的结果

Question

我写了一个简单的基准，也许是错的，并且给我带来了意想不到的结果……这就是为什么我要请你解释一下，甚至更好地纠正我的例子。

using System;
using System.Threading.Tasks;

namespace AsyncTest
{
    class Program
    {
        static void Main(string[] args)
        {
            var startDate = DateTime.Now;

            for (int i = 0; i < 10000; i++)
            {
                InsertEntity(i);
                Console.WriteLine($"{i}");
            }

            var endDate = DateTime.Now;

            Console.WriteLine($"Total elapsed time: {(endDate - startDate).TotalMilliseconds}");
        }

        static void InsertEntity(int i)
        {
            using (var context = new TestContext())
            {
                var entity = new Entity
                {
                    Code = $"Code {i}",
                    Name = $"Name {i}",
                    Description = $"Description {i}"
                };
                context.Entities.Add(entity);
                context.SaveChanges();
            }
        }
    }
}

  

总经过时间：9585ms

using System;
using System.Threading.Tasks;

namespace AsyncTest
{
    class Program
    {
        static void Main(string[] args)
        {
            var startDate = DateTime.Now;

            for (int i = 0; i < 10000; i++)
            {
                InsertEntity(i).Wait();
                Console.WriteLine($"{i}");
            }

            var endDate = DateTime.Now;

            Console.WriteLine($"Total elapsed time: {(endDate - startDate).TotalMilliseconds}");
        }

        static async Task InsertEntity(int i)
        {
            using (var context = new TestContext())
            {
                var entity = new Entity
                {
                    Code = $"Code {i}",
                    Name = $"Name {i}",
                    Description = $"Description {i}"
                };
                await context.Entities.AddAsync(entity);
                await context.SaveChangesAsync();
            }
        }
    }
}

  

总经过时间：13479ms

我希望反过来，因为异步编程可以在I / O绑定操作期间释放线程...这是正确的吗？那么为什么它实际上要慢一些？