Let win xp use L2 cache properly

[sj1183]

For users of Windows 2000 or XP you actually have to tell the OS what size L2 cache your processor has otherwise it won't be used properly! Luckily it's fairly easy to fix.

Click on the Start button then go to run. From there type REGEDIT and press the "Ok" button. After it opens the Registry Editor follow this path. hkey_local_machine, System, CurrentControlSet, Session Manager, Memory Management

Once you're in the Memory Management folder look for the DWORD value
secondleveldatacache.
Right click on that and go to modify. Very important you have to change the Base from Hexidecimal to Decimal before modifying the values. After that's done just punch in your L2 cache size so if you're using an AthlonXP since the CPU has 256KB L2 Cache you enter 256. For Duron's enter 64 and for P4 Northwood's enter 512.
After that's done you should notice your programs now have quite a bit more zip and the system is less sluggish because Windows now knows how to use your L2 cache properly.

[Greenhat]

Interesting tip. I've made the change (missing one level in your location description), should be:
HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Session Manager/Memory Management

[Sonny]

Good tip. Will try. Greenhat has got to be Al. :D

[uffbros]

What would a Intel Celeron L2 Cache be for this purpose? Thanks

[Sonny]

I don't believe the Celeron has a a large L2 cache. I could be wrong, so download WCPUID from http://www.h-oda.com to check your CPU for L2 cache's size.

[sj1183]

Thanks for the assist Greenhat.
Take care.
Sandy

[Slartibartfast]

Originally posted by uffbros
What would a Intel Celeron L2 Cache be for this purpose? Thanks

Hi,

I have a 600 Celery and WCPUID says it has an L2 cache of 128K

[uffbros]

Thanks Slartibartfast..... My SIL has a Celeron and I was just wondering so I could tweak hers. I have an Athalon.

[anthonyS]

Thanks for the tip :-)

[maximafia]

I seem to recall that Celerons below a certain speed had no L2 cache. Don't quote me, but I believe is was something like 366 or 400 MHz. I know my old Celeron 300 had no L2 cache.

[bluebird]

Right click on that and go to modify. Very important you have to change the Base from Hexidecimal to Decimal before modifying the values. After that's done just punch in your L2 cache size so if you're using an AthlonXP since the CPU has 256KB L2 Cache you enter 256. For Duron's enter 64 and for P4 Northwood's enter 512.



**** I did this but do I put 256kb or just 256 then I click ok,,,,,, thank you

[sj1183]

Hi Bluebird,
You enter 256.
Take care.
Sandy

[Bob G]

Then there's this:

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

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.

http://support.microsoft.com/default.aspx?scid=kb;EN-US;q183063

And this:

Do not change the SecondLevelDataCache entry

Some third-party sources have erroneously reported that modifying the SecondLevelDataCache registry entry in HKEY_LOCAL_MACHINE \System \CurrentControlSet \Control \Session Manager\Memory Management can 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.

http://www.microsoft.com/technet/treeview/default.asp?url=/TechNet/prodtechnol/windows2000serv/reskit/serverop/part2/sopch06.asp

Bob

[misterhy]

misterhy here. I am running a fairly new compaq with Pentium 4,1.5 gig and when I ran the Belarc advisor it tells me that I have a 256 L2 cache. I did nothing nor will I do enything as this PC is plenty fast enough for me. WinXP, 512 meg sdram. I guess the newer units don't need the tweak that the older ones do.
Great tip anyway.

:D :cool:

[old dude]

Originally posted by Greenhat
Interesting tip. I've made the change (missing one level in your location description), should be:
HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/Session Manager/Memory Management


Hey Al, good to see you here........