What is the Object Memory Overhead in .NET and How Does it Vary Across Implementations?

Object Memory Overhead in .NET

When dealing with objects in the .NET framework, it's essential to understand the memory requirements associated with them. Beyond the storage space for an object's properties and fields, there is an additional per-object overhead incurred by the internal workings of .NET.

This overhead incorporates the memory required for elements like object headers, which contain information such as the object's type, allocation size, and references to the garbage collector. Determining the precise memory overhead depends on the specific .NET implementation.

Overheads in Different Implementations

For Microsoft .NET CLR v4:

• x86 CLR: 8 bytes per object
• x64 CLR: 16 bytes per object

Minimum Object Sizes

While the overhead varies depending on the implementation, there are minimum sizes below which objects cannot go. These sizes are:

• 12 bytes for x86 CLR
• 24 bytes for x64 CLR

Despite the technical overhead of 8 or 16 bytes, objects can store 4 or 8 bytes of actual data before additional memory is allocated. This effectively provides a "free" buffer of space for small data members.

For a deeper dive into the specifics of object memory allocation in .NET, refer to the blog post "Of memory and strings."

The above is the detailed content of What is the Object Memory Overhead in .NET and How Does it Vary Across Implementations?. For more information, please follow other related articles on the PHP Chinese website!