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hmar

Wrong CPU setting?

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I downloaded a while ago an article about installing Windows XP on a Vista system. Well it didn't work on my system because it refuses to boot up my XP CD. But at the end of the article there were the paragraphs I mention here below (on my system the level2 cache was set to 0!). Does it has an influence on the FPS...I don't know! I am really sorry but I don't know the original author:The final thing I want to mention is that both XP and Vista do not utilize your CPU correctly. Most CPU’s have a great amount of 2nd level cache on board, but Windows by default only recognizes 256 Kb of it.To enable your full 2nd level cache of your CPU in both operating systems (and you have to do this first in Vista, then again in XP) is:1.Open the Start Menu.2.In the white line (Start Search) area, type regedit and press Enter. (Click Continue for UAC prompt for Vista users unless you have already put UAC into quiet mode.)3.In regedit, go to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management4.In the right pane, right click SecondLevelDataCache and click Modify.5.Type in the value for your CPU L2 size.Here is a basic chart for the values for 2nd level cache. To determine how much 2nd level cache your CPU has, use CPU-Z located at http://www.cpuid.com/cpuz.php . All you need to check in this utility is how much 2nd level cache your CPU has.L2 Size: Type value in bold below. Make sure you use the correct value for the correct setting. If the dot is in Hexadecimal, enter the hexadecimal value. If the dot is in Decimal, enter the decimal value.DECIMAL---------HEXADECIMAL256 KB-----------100 (hex)512 KB-----------200 (hex)1024 KB (1MB)----400 (hex)2048 KB (2MB)----800 (hex)4096 KB (4MB)----1000 (hex)6144 KB (6MB)----1800 (hex)8192 KB (8MB)----2000 (hex)12288 KB (12MB)--3000 (hex)16384 KB (16MB)--4000 (hex)6.Click OK to apply. 7.Close regedit.8.Restart the computer to apply the change. You will need to do this in both Vista and XP separately to take advantage of your CPU’s power.Also Vista Compatible programs are only compatible under Vista SP 1. Most programs needed the hotfixes that SP 1 provides. Also, programs that state XP / Vista compliant, you may need to set the program for XPSP 2 compatibility and check Disable Desktop Composition and Disable Visual Themes for them to work correctly and put a check mark into Run the program as an Administrator so that the program is able to save your personal settings. You can find where to adjust these settings by right clicking the program executable, select properties, then in the window that appears click the Compatibility tab. Your settings will be listed here. Once you have made your settings, click OK and the settings will be applied the next time you launch the program.Rgds,Hugo

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HugoDoes this registry edit work?I'm intrigued, but at the same time very wary of breaking the XP registry - always get nervous when a "performance increase" requires a registry edit....Let us know!RegardsChris

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HugoDoes this registry edit work?I'm intrigued, but at the same time very wary of breaking the XP registry - always get nervous when a "performance increase" requires a registry edit....Let us know!RegardsChris
The OP doesn't specify a source for this information; here's what MS has to say.From the Microsoft knowledge base: http://support.microsoft.com/kb/183063 - here's the gist of the article regarding this setting...'SecondLevelDataCache records the size of the processor cache, also known as the secondary or L2 cache. If the value of this entry is 0, the system attempts to retrieve the L2 cache size from the Hardware Abstraction Layer (HAL) for the platform. If it fails, it uses a default L2 cache size of 256 KB. If the value of this entry is not 0, it uses this value as the L2 cache size. This entry is designed as a secondary source of cache size information for computers on which the HAL cannot detect the L2 cache. 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. SecondLevelDataCache can increase performance by approximately 2 percent in certain cases for older computers with ample memory (more than 64 MB) by scattering physical pages better in the address space so there are not so many L2 cache collisions. Setting SecondLevelDataCache to 256 KB rather than 2 MB (when the computer has a 2 MB L2 cache) would probably have about a 0.4 percent performance penalty.'further... from http://support.microsoft.com/kb/228766'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.'The official word is not to mess about with this setting - let the OS take care of it.DJ

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The OP doesn't specify a source for this information; here's what MS has to say.From the Microsoft knowledge base: http://support.microsoft.com/kb/183063 - here's the gist of the article regarding this setting...'SecondLevelDataCache records the size of the processor cache, also known as the secondary or L2 cache. If the value of this entry is 0, the system attempts to retrieve the L2 cache size from the Hardware Abstraction Layer (HAL) for the platform. If it fails, it uses a default L2 cache size of 256 KB. If the value of this entry is not 0, it uses this value as the L2 cache size. This entry is designed as a secondary source of cache size information for computers on which the HAL cannot detect the L2 cache. 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. SecondLevelDataCache can increase performance by approximately 2 percent in certain cases for older computers with ample memory (more than 64 MB) by scattering physical pages better in the address space so there are not so many L2 cache collisions. Setting SecondLevelDataCache to 256 KB rather than 2 MB (when the computer has a 2 MB L2 cache) would probably have about a 0.4 percent performance penalty.'further... from http://support.microsoft.com/kb/228766'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.'The official word is not to mess about with this setting - let the OS take care of it.DJ
Thanks DJ - no doubt the endless search for performance increases goes on........as an American car manufacturer once said "there ain't no replacement for displacement"RegardsChris

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