CPU L2 cache

Cochise · Post by **Cochise** » Mon Sep 26, 2005 12:15 pm

I've just read this on a magazine:

verify XP is correctly using L2 cache;

the key SecondLevelDataCache in the pathHKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlSession ManagerMemory Management of the registry, has to be set to values of 200 for 512KB L2 cache processors, 400 for 1MB.

It was set to 0 here.

valis · Post by **valis** » Mon Sep 26, 2005 2:42 pm

http://support.microsoft.com/kb/q183063/

Cochise · Post by **Cochise** » Mon Sep 26, 2005 3:18 pm

Right. Seems to be a useless tweak.
With 0 value the OS get L2 cache amount from the HAL...
But I can't find any OS report about L2 cache amount...

valis · Post by **valis** » Mon Sep 26, 2005 5:11 pm

Search MSDN & find out what the call is to request L2 cache size. I used to use this tweak years ago (I actually had a dual p133 board with scsi onboard) and I recall with NT4 & My dual P2 xeons it was no longer necessary. I also recall that the only thing it seemed to affect was the OS, Softimage and Photoshop were able to query the cpu directly,. I would hazard a guess that many audio apps do the same, especially with MS's byzantine labyrinth of system calls in WinXP.

<font size=-1>[ This Message was edited by: valis on 2005-09-26 18:12 ]</font>

Cochise · Post by **Cochise** » Tue Sep 27, 2005 6:00 am

The OS could succeed in retrieving that data if a P4 is in use.