Microsoft Exchange Performance Counters

Microsoft Exchange Common Memory counters

The following table shows common memory counters.

Counter Name	Description
Memory\%Committed Bytes in Use
Memory\Available Mbytes	Shows the amount of physical memory, in megabytes (MB), immediately available for allocation to a process or for system use. It's equal to the sum of memory assigned to the standby (cached), free, and zero page lists. For a full explanation of the memory manager, refer to Microsoft Developer Network (MSDN) or "System Performance and Troubleshooting Guide" in the Windows Server 2003 Resource Kit.
Memory\Cache Bytes	Shows the current size, in bytes, of the file system cache. By default, the cache uses up to 50% of available physical memory. The counter value is the sum of Memory\System Cache Resident Bytes, Memory\System Driver Resident Bytes, Memory\System Code Resident Bytes, and Memory\Pool Paged Resident Bytes.
Memory\Committed Bytes	Shows the amount of committed virtual memory, in bytes. Committed memory is the physical memory that has space reserved on the disk paging files. There can be one or more paging files on each physical drive. This counter displays the last observed value only; it isn't an average.
Memory\Pool Nonpaged bytes	Consists of system virtual addresses guaranteed to be resident in physical memory at all times and can thus be accessed from any address space without incurring paging input/output (I/O). Like paged pool, nonpaged pool is created during system initialization and is used by kernel-mode components to allocate system memory.
Memory\Pool Paged bytes	Shows the portion of shared system memory that can be paged to the disk paging file. Paged pool is created during system initialization and is used by kernel-mode components to allocate system memory.