在BIOS內雖然有L2 的開啟的Function
但到了作業系統卻未必能完全的發揮
透過Regedit 來修改Winodws的登錄檔
來開啟最大的L2 快取

方法
http://home.anet.net.tw/aa013797/l2.jpg

開啟登錄檔編輯器 到
HKEY_LOCAL_MACHINE\SYSTEM\
CurrentControlSet\Control\Session Manager\Memory Management

2
http://home.anet.net.tw/aa013797/l202.jpg

在SecondLevelDataCahce 值上選修改
在值的資料打上CPU的L2大小，並將底數改為十進位即可

像DURON是64 , P4 AthlonXP是256 , P4(Northwood) Athlon (Barton)是512
Athlon 64 P4 (Prescott) 是1024

此設定支援WinXP WIN2K , 不支援WIN98 WINME

資訊來源 , 6月號PCDIY

贊助商連結

實証結果沒啥效果..

Caution Against Resetting the Secondary Cache

The Windows 2000 registry contains configuration data that is important for memory usage. Some third-party sources have erroneously reported that system performance can be enhanced by modifying the following registry key:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory Management\SecondLevelDataCache.

Although it is possible to change this value from the default value of 0, in most cases doing so does not improve performance. Microsoft does not recommend changing this setting. When this key's value is set to 0, the system attempts to retrieve the level-2 processor (L2) cache size from the HAL for the platform. If it does not obtain this value, the system sets a default size of 256 KB for the L2 cache.

For additional information about file caching, please see the following article in the Microsoft Knowledge Base:

183063 (http://support.microsoft.com/?id=183063) Detailed Explanation of SecondLevelDataCache

Or, see the "Windows 2000 Resource Kit," Chapter 28, "Evaluating Memory and Cache Usage."

run regedit and edit the key value :
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\
Memory Management\SecondLevelDataCache
因為最近買了一台 nb (Centrino 晶片組)，重灌 winXP的話，
它無法抓到正確的 Cache 值…
如果有跟我一樣狀況的人，可以去檢查一下，並改成符合CPU的 cache memory size
我改完以後，開機速度就變的比較快，
但我還有改其它的設定，所以不確定是不是這個影響…
不過總而言之，應該是會比較快啦…^^ ....Good luck....

　　在此還是要聲明一下，除非真的有必要，否則不建議去改此一參數。微軟的技術文件就有特別提到：外面的非官方網站有很多文章說改變此一參數有助於提昇效能的說法是不完全正確的。

　　且 http://www.regedit.com 網站有提到：This tweak is only useful for older processors with the cache located external to the CPU.（在此只是提出有此一說法，但不保證這麼說一定是對的。）