System

GetMemoryManagerState returns a structure containing memory usage statistics for each block type - small, medium and large blocks. In the current implementation, small blocks are blocks that are smaller than roughly 2.5K, large blocks are blocks that are larger than roughly 256K, and medium blocks are the sizes in between. It provides additional detail for the small block type (which is usually the most frequently used block type) down to each individual block size.  

The structure returned by this procedure makes a distinction between the reserved address space and the allocated address space for each block type. The allocated address space is that part of the address space that is currently in use by the application, i.e. memory that was allocated through GetMem and not yet freed. The reserved address space is the amount of address space that was obtained from the operating system for current and future use by the application, i.e. the allocated address space plus all overhead. 

Memory Management 

Configuring the Memory Manager 

Monitoring the Memory Manager