Dapper

gistfile1.cs

// inserting 500 products. 
// even when Dapper is running the same sql as EF it is twice as fast. 

var products = Enumerable.Range(1, 500).Select(_ =>
        new Product
        {
            Name = Guid.NewGuid().ToString(),
            Description = Guid.NewGuid().ToString()
        }
    ).ToList();

Stopwatch sw = Stopwatch.StartNew();
using (var ctx = new MyContext(cnn))
{
    foreach (var p in products) ctx.Products.Add(p);
    ctx.SaveChanges();
}

Console.WriteLine(sw.ElapsedMilliseconds);
// 2023

sw.Restart();
cnn.Open();
foreach (var p in products)
{
    cnn.Query<int>(@"insert [dbo].[Products]([Name], [Description])
values (@Name, @Description)
select [Id]
from [dbo].[Products]
where @@ROWCOUNT > 0 and [Id] = scope_identity()", p);
}

Console.WriteLine(sw.ElapsedMilliseconds);
// 951

sw.Restart();
cnn.Execute("insert Products(Name,Description) values(@Name,@Description)", products.Select(p => new { p.Name, p.Description }));
Console.WriteLine(sw.ElapsedMilliseconds);
// 777

Console.ReadKey();