Modifying Level 2 Cache does not accelerate Windows XP

Among the many XP optimization techniques, a popular saying is that Windows XP requires you to manually open the second-level cache of the CPU to maximize the CPU efficiency. This statement has been widely used. The "Windows optimization master", one of the most popular Windows system optimization software, also holds this view, in its optimization settings column, the option to optimize the CPU second-level cache is available.

Let's first look at how this so-called optimization technique tells us.

[In Windows XP, the second-level CPU cache is not enabled by default. To improve system performance, we can enable it by modifying the registry or using software such as "Windows optimization master.

Run the Registry Editor, expand the HKEY_LOCAL_MACHINESystemCurrentControlSetControlSession ManagerMemory Management Branch, double-click "SecondLevelDataCace" in the window on the right, and then fill in the second-level memory of the CPU used by the current computer in the displayed.

The second-level cache of the saiyang processor is kb and its value should be set to 80 (hexadecimal, the same below ). P Ⅱ, P Ⅲ, and P4 are both 512KB Level 2 caches, which should be set to 200; P Ⅲ E (EB) and P4 Willamette only have 100 kb Level 2 caches, which should be set; AMD Duron only has 64 kB Level 2 cache, should be set to 40; K6-3 has kb Level 2 cache; Athlon has kb Level 2 cache; Athlon XP has kb Level 2 cache; Athlon XP (Barton core) it has a kb level-2 cache.

You can also use the Windows optimization master to correctly set the second-level cache of the CPU: Start the Windows optimization master and select "system performance optimization". In "file system optimization", the top is the setting item about the second-level cache of the CPU. Drag the slider to the corresponding position, save the settings, and restart the computer .]

Is that true?

We found the following content in Microsoft's knowledge base: The SecondLevelDataCache key value in "HKLMSYSTEMCurrentControlSetControlSession ManagerMemory Management" is only available in Windows XP from the Hardware Abstraction Layer (Hardware isolation action Layer) when the second-level cache (L2) of the CPU fails to be read, the data of the SecondLevelDataCache key is read. In addition, the value of SecondLevelDataCache is 0, indicating that the second-level cache is 256KB.

In a Knowledge Base Article, we also found the words "Do not change the SecondLevelDataCache entry, in this article, it is pointed out that some third-party documents claim that modifying the SecondLevelDataCache key value can improve system performance. The value of the second-level cache is detected by the operating system and is not affected by the SecondLevelDataCache value.

From the Microsoft Knowledge Base Article, we can see that the so-called Windows XP system requires users to manually open the second-level cache. Windows XP reads the second-level cache value of the CPU Based on the hardware abstraction layer. The value of SecondLevelDataCache is read only when reading fails. The default value 0 of SecondLevelDataCache indicates that the second-level cache is 256KB, rather than being disabled. Therefore, the second-level cache of the CPU is enabled at any time, and you do not need to modify it on your own.