Windows XP and L2 Cache

[CCW]

Is it true that Windows XP does not recognise a processor Level 2 cache? Does anyone have any info on this please?

Thanks,
Craig

[TheDude]

by default windows doesn't recognise your L2 cache on processor and doesn't make use of it, to enable it run regedit and navigate to

HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Control > Session Manager > MemoryManagment

there is a DWORD called "SecondLevelDataCache" double click it, select Decimal and set the amount of L2 cache you have (e.g. if you have 256KB, then just type 256, and make sure you enter it in Decimal, not Hexadecimal)
:D

[CCW]

Thanks for that. Do you know why Windows doesnt use L2 cache? Surely it would be much faster with it?

Thanks,
Craig

EDIT - Dude, do you have mIRC?

If so you can join us if you want, channel is #xtremesystems
server is QuakeNet or just click the link to the IRC room in my sig if you want.

Craig

[TheDude]

I think xp just has trouble finding it for some reason, not sure why, this is supposed to fix that.

I don't have mirc...but may try it in the future...thanks my friend.:D

[GreenBeret]

I'm 99.99% sure that I've read that the default "0" means Auto-Detect (size) rather than "Windows doesn't use the L2 cache". Your xGHz CPU would crawl like a 10MHz chip if the L2 cache is not used.

[IFMU]

Curious, would it be any different for a duallie? Imaging not, but just a lil curious...

[TheDude]

Originally posted by Niko
I'm 99.99% sure that I've read that the default "0" means Auto-Detect (size) rather than "Windows doesn't use the L2 cache". Your xGHz CPU would crawl like a 10MHz chip if the L2 cache is not used.

I think you are correct on that, adding the string is supposed to bypass the auto detect because there are supposed to be problems with it working correctly all the time. I imagine it's the same with duallie but honestly don't know. I only just recently heard of this issue and am passing along info published from several different people on the net. I have no 1st hand knowledge of this. Don't think it can harm anything to go ahead and plug the value in hard coded.

[FragMagnet]

I remember this tweak from the W2K tweak guides. I still use it, but it defaults to 256 on both W2k and XP. Not sure if there is a detection method after that though. I've read elsewhere that tweak is mainly aimed at the older Pentiaums and 1st Athlons, where the L2 was external.