How much memory does a C# reference consume? [duplicate]

Question

How much memory does a C# reference consume? Does References consumes memory as much as the object itself?

Answer 1

A reference is implemented as a pointer, so in an application that runs in x86 mode (32 bit), a reference is four bytes, and in x64 mode (64 bit), a reference is eight bytes.

As the reference is just a pointer to an object, the reference is the same size regardless of what it is pointing to, or even if it doesn't point to anything at all (null).

Answer 2

From C# 5.0 in a Nutshell: The Definitive Reference in page 22;

Reference types require separate allocations of memory for the reference and object. The object consumes as many bytes as its fields, plus additional administrative overhead. The precise overhead is intrinsically private to the implementation of the .NET runtime, but at minimum the overhead is eight bytes, used to store a key to the object’s type, as well as temporary information such as its lock state for multithreading and a flag to indicate whether it has been fixed from movement by the garbage collector. Each reference to an object requires an extra four or eight bytes, depending on whether the .NET runtime is running on a 32- or 64-bit platform.