Which sorting algorithm is used in stl and .net base library default search?

Question

I am now working on an imprived version of merge sort. I implemented it with C++ and C#. Then compared them with the stl sort and array.sort() algorithm respectively. In C++ I have got an equal (sometimes better) result. But in C#, I had to use unsafe code for using pointers. Here the performence is not that much comparable with default sort. So, I want to know-

1. Which algorithms are used in stl and .net base class library?(Better with links)
2. Do unsafe codes has performence issues?
3. Any suggessions for me regarding measuring the performence of the new algorithm?

Answer 1

.NET uses a variation of Quicksort (Sedgewick's median of 3 Quicksort).

Unless you are an expert in sorting, I would be surprised if you can beat the built-in Sort over a wide range of data (including random, already ordered and reverse ordered sets). Resorting to unsafe code is usually a bad idea...