By default, Windows NT and 2000 do not utilize a second level cache larger than 256KB. If you have a Xeon, or even a chip with 512KB, you probably want to get the most out of it.
Here is how:
If your second level cache is larger than 256KB, add a registry setting to allow NT to be able to access over 256KB on the second level cache. Be careful with this setting; it could slow your server down.
Before you add the new setting, make sure that you have backed up the registry. That way, if there is a problem because of your editing, then you can restore the registry from the backup, and you will be back where you started before you did any modifications.
To add the setting, open this key in REGEDIT.EXE:
Right click in the right-hand pane, and click New/DWORD Value on the context sensitive menu that comes up. REGEDIT will add a new DWORD value. Then right-click on the new value, and click Modify on the context-sensitive menu. In the dialog box that comes up, enter the decimal value below, and click the decimal radio button.
SecondLevelCache REG_DWORD:1024 (decimal)
Click out to save the new value.
- I think the registry key mentioned in this tip is wrong. It is supposed to be secondleveldatacache not secondlevelcache. The missing word is data. Check out the following technet document: http://www.microsoft.com/TechNet/winnt/regtwk.asp Shabbir S. Talib
- But the Windows 2000 Server Resource Kit says this: Do not change the SecondLevelDataCache entry. Some third-party sources have erroneously reported that modifying the SecondLevelDataCache registry entry in
HKEY_LOCAL_MACHINESystemCurrentControlSet ControlSession ManagerMemory Managementcan 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. Is this the same thing? Glen Conway
- Technically, shouldn't we be using regedt32.exe rather than regedit on NT/2000 boxes?Chris Laimit
- I've read more than one article that states: "This item is obsolete. On all modern systems, that is all supported processors/systems, it should not be an issue. This is not related to the hardware; it is only useful for computers with direct-mapped L2 caches. Pentium II and later processors do not have direct-mapped L2 caches."Glenn Weatherford
This was first published in April 2001