Optimizing Your Memory Configuration

The default memory-management settings for your system are optimal in most situations and do not need to be changed. However, the system can provide a much larger working set and additional virtual address space for the system cache if some settings are manually tuned. These settings include the following registry entries in the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control \Session Manager\Memory Management subkey:

  • LargeSystemCache . A value of 1 maximizes the size of the system cache's working set and, with PagedPoolSize set to 192000000 and SystemPages set to 0, provides a large virtual address space for the cache, provided that Terminal Services and the /3GB switch are not used. In addition, the maximum working set and large virtual address space for the file system cache are unavailable if Driver Verifier, a tool for testing kernel drivers, is enabled with the special pool. For information about Driver Verifier, see the Driver Development Kits link on the Web Resources page at https://windows.microsoft.com/windows2000/reskit/webresources .

  • PagedPoolSize . Changing this to 0xFFFFFFFF or leaving it at the default of 0 maximizes the size of the virtual address space used for the paged pool. To set aside extended virtual address space for the file system cache, change this value to 192000000, set LargeSystemCache to 1, and set SystemPages to 0.

  • SystemPages . Changing this to 0xFFFFFFFF provides an additional 464 MB of system page table entries for the virtual address space. Notice that making this change prevents expanding the system cache by 464 MB (limiting it to 512 MB) and limits the paged pool size to 192 MB, provided PagedPoolSize is not set to 0xFFFFFFFF to obtain the maximum virtual address space for the paged pool.

Notice that you have the option of changing the settings for LargeSystemCache in the user interface (using the Server Optimization tab in File and Printer Sharing for Microsoft Networks properties). However, you can only change the settings of SystemPages , PagedPoolSize , and NonPagedPoolSize using a registry editor.



Do not use a registry editor to edit the registry directly unless you have no alternative. The registry editors bypass the standard safeguards provided by administrative tools. These safeguards prevent you from entering conflicting settings or settings that are likely to degrade performance or damage your system. Editing the registry directly can have serious, unexpected consequences that can prevent the system from starting and require that you reinstall Windows 2000. To configure or customize Windows 2000, use the programs in Control Panel or Microsoft Management Console (MMC) whenever possible.

If you are using Terminal Services or your system is configured to start with the /3GB switch, these features consume the extra virtual address space that you might otherwise allocate to the system cache or the paged pool and that space is unavailable.

Do not change the SecondLevelDataCache entry
Some third-party sources have erroneously reported that modifying the SecondLevelDataCache registry entry in HKEY_LOCAL_MACHINE\System\CurrentControlSet \Control\Session Manager\Memory Management can enhance system performance. The second level (L2) cache is recognized by the operating system and is fully utilized regardless of the setting of this parameter.