Tech Tip: Adjust the Level 2 cache setting

During Windows XP installation, Setup queries the system processor to determine the size of the Level 2 cache. However, it doesn't always succeed. When this happens, Setup configures a default setting of 256 KB in the registry.

If your computer has a larger Level 2 cache than Setup configured in the registry, your system won't perform optimally. To significantly increase the performance of your system, change the value in the registry to match your Level 2 cache.

Here's how:

  1. Launch the Registry Editor (Regedit.exe).
  2. Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management.
  3. Double-click SecondLevelDataCache DWORD value.
  4. Using the options below, change the value in the Value Data text box to a number that matches the size of your Level 2 cache. Then click OK.
    Level 2 cache            Value Data setting
    256 KB                       0
    512 KB                       200
    1024 KB                     400
  5. Click OK and close the Registry Editor.

You may need to restart the system or log out of Windows XP for the change to take effect.

If you're not sure of the actual size of your system's Level 2 cache, copy this script and save it as L2Cache.vbs:

Set ProSet = GetObject("winmgmts:").InstancesOf("Win32_Processor")
For each Pro in ProSet
WScript.Echo "Level 2 Cache:" & "  " & Pro.L2CacheSize & " KB"

Double-click the script to run it, and you'll see a dialog box that displays the size of your system's Level 2 cache.

Note: Editing the registry is risky, so be sure you have a verified backup before making any changes.

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