Why is .NET faster than C++ in this case?

Question

Make sure you run outside of the IDE. That is key.

-edit- I LOVE SLaks comment. \"The amount of misinformation in these answers is staggering.\" :D

Answer 1

Speculation 1

Garbage collection procedure might play a role.

In the C++ version all memory management would occur inline while the program is running, and that would count into the final time.

In .NET the Garbage Collector (GC) of the Common Language Runtime (CLR) is a separate process on a different thread and often cleans up your program after it's completed. Therefore your program will finish, the times will print out before memory is freed. Especially for small programs which usually won't be cleaned up at all until completion.

It all depends on details of the Garbage Collection implementation (and if it optimizes for the stack in the same way as the heap) but I assume this plays a partial role in the speed gains. If the C++ version was also optimized to not deallocate/clean up memory until after it finished (or push that step until after the program completed) then I'm sure you would see C++ speed gains.

To Test GC: To see the "delayed" .NET GC behaviour in action, put a breakpoint in some of your object's destructor/finalizer methods. The debugger will come alive and hit those breakpoints after the program is completed (yes, after Main is completed).

Speculation 2

Otherwise, the C# source code is compiled by the programmer down to IL code (Microsoft byte code instructions) and at runtime those are in turn compiled by the CLR's Just-In-Time compiler into an processor-specific instruction set (as with classic compiled programs) so there's really no reason a .NET program should be slower once it gets going and has run the first time.