因為是微軟自己說的,原文如下:

Getting the Most from Your Cache
By default, the NT HAL tries to recognize the amount of L2 cache on your motherboard. Sometimes it succeeds, and sometimes it fails. You can make sure that the HAL knows how much cache you have installed by checking the value of the SecondLevelDataCache REG_DWORD value under the HKLM\System\CurrentControlSet\Control\Session Manager\Memory Management key.

When this value is 0, that tells the HAL that you have 256Kb of L2 cache. If you have a different amount installed, set SecondLevelDataCache to the amount, in Kb, of cache you've actually got. For example, if you have a 512Kb cache, set the value to be a decimal(十進位) value of 512 or a hex(十六進位) value of 0x200. If you get this wrong, your machine may be unstable, so make sure to enter the right value in the right base

http://www.microsoft.com/technet/pr...ion126121120120

我剛剛進去看,真的是設0,當成256KB了,所以沒抓正確,自己改了 ,反正沒損失