Evaluating Memory and Cache Usage

Start your monitoring efforts by knowing that you have at least the minimum amount of memory required to run Windows 2000. Windows 2000 Professional requires at least 32 megabytes (MB) of memory.

The memory recommendation for Windows 2000 Professional is based on a typical desktop configuration including a business productivity application, such as a word processor or a spreadsheet program, an e-mail application, and a Web browser.

There are a few different ways to determine the amount of memory on your computer. You can find the amount of physical memory installed on your system by clicking the Performance tab in Task Manager. Or you can find the amount of available RAM by double-clicking System in Control Panel , and then clicking the General tab.

Note

You can see the memory configuration on local or remote systems by using System Information. For more information about System Information, see Windows 2000 Professional Help.

The operating system distinguishes memory usage by applications and services depending on whether the usage involves the paged or the nonpaged pool. The paged pool contains memory for objects used by applications and services that can be paged to disk; objects in the nonpaged pool cannot be paged to disk. The operating system determines the size of each pool based on the amount of physical memory present. Memory pool usage can be an important factor in evaluating memory usage by your applications. For more information about memory pools, see Investigating User-Mode Memory Leaks and Investigating Kernel-Mode Memory Leaks later in this chapter.

The file system cache, which is a subset of physical memory used for fast access to data, and the disk paging file , which supports virtual memory , influence the amount of memory used by the operating system and applications. (The disk paging file, also called a swap file, is a file on the hard disk that serves as temporary, virtual memory storage for code and data.) Virtual memory is the space on the hard disk that Windows 2000 uses as memory. For purposes of monitoring, the most important types of virtual memory are committed memory (shown under Memory\Committed Bytes) that the system sets aside for a process in the paging file and available memory (shown under Memory\Available Bytes) that is not in use by a process. (Another type of memory managed by Windows 2000 is reserved memory, which the system sets aside for a process, but which might not be entirely used.) The following sections describe the influence of the cache and the paging file on performance and explain how best to adjust these for optimal memory usage.