Colin's Weekly Tip: Let Win2k/XP use your L2 cache properly [Archive]

Colin

06-15-04, 02:25 PM

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, Control, 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 (Thoroughbred) 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.

EDIT: Adding more CPU types.
P4 Prescott - 1024
AthlonXP Barton - 512
Athlon64 NewCastle - 512
Athlon64 ClawHammer - 1024
AthlonFX - 1024
Sempron - 256

Hope you don't mind Colin :)
~Westy

zogmool

06-15-04, 02:25 PM

Colin, I believe you've forgotten one of the keys. I found this setting under: hkey_local_machine, System, CurrentControlSet, *Control*, Session Manager, Memory Management

GNXtreme

06-15-04, 02:25 PM

P4 has 512k

CHE

06-15-04, 02:25 PM

P4 Northwood has 512 kB L2, but a 1.3 Ghz P4 sounds like it might be an older Willamette which has 256 kB L2.

GNXtreme

06-15-04, 02:25 PM

CHE you are right...I don't know my intel.

CHE

06-15-04, 02:25 PM

LOL, I had to look it up <img src="i/expressions/face-icon-small-happy.gif" border="0">

GNXtreme

06-15-04, 02:25 PM

Cheater!

jan_hut

06-15-04, 02:25 PM

I'm kind of lost here. I have used this tweak changing the value in 512 (decimal) since I have a P4 2.0a. I also changed the value of LargeSystemCache to 1 and then went to HKEY_CURRENT_USER---->Control Panel------->Desktop and set MenuShowDelay to 0 instead of the standard 400. Apparently this wasn't such a good idea since after (trying) to reboot the machine crashed. No problem we say....just give booting in Safe Mode a try. Same problem. Well then just boot to "Last know Good Configuration". That looked more promising since it didn't crash before the blue windows logon screen. Trying the "last know......" once more did the trick and I was back in business, or so I thought. Upon doubleclicking on the shortcut to my dial-up account nothing happened. I checked under My Network Connections and it was gone there too so not surprising the shortcut didn't work. Usually not a problem. Just click on "create a new connection" and the wizard takes you through it. And there is my problem, one I hope one of you can help me out with. Both "connect using a dial-up modem" and the PPPoE options are greyed out! I can only connect to the internet using an always on connection (which is the third option). Now I know this is just a little entry in the registry that has somehow been removed or altered but I have no clue which. Any help would be very much appreciated! I'm running Windows XP Pro Corp. P.S. Modem works fine (before anyone asks)

sir-lancelot

06-15-04, 02:25 PM

<img src="i/expressions/face-icon-small-sad.gif" border="0">How do I find out what my L2 cache size is. I have an AMD Athlon 751MHz processor????

Part16John

06-15-04, 02:25 PM

thanks for the tip, have to give it a try when i get home, nice site by the way<img src="i/expressions/face-icon-small-smile.gif" border="0">

GNXtreme

06-15-04, 02:25 PM

Duron L1=128k L2=64k Athlon L1=128k L2=256k XP L1=128k L2=256k

CHE

06-15-04, 02:25 PM

jan_hut, I don't have XP so I don't know the particulars, but can't you restore your registry from an older backup? Microsoft has an article about running System Restore to implement the registry that windows (hopefully) automatically backs up. Here: <a target=new class=ftalternatingbarlinklarge href="http://;Q306084]http://support.microsoft.com/default.aspx?scid=kb;[LN];Q306084">http://support.microsoft.com/default.aspx?scid=kb;[LN</a> Obviously you would want to restore the most recent registry that was backed-up before you encountered the problem. Obviously restoring a registry that was backed up after the problem started won't help. Understand that any programs installed or options configured since the date and time of the registry backup my not function properly, but you can always undo the restore.

jan_hut

06-15-04, 02:25 PM

actually I think that is where the problem came from. I bootred with "last know good settings" which I think should include the "last known good" registry as well. It's an odd problem, since everything is running smoothly. Just as if a sysadmin has disabled any remote networking outside of my network that requires authentication (VPN is greyed out as well).

CHE

06-15-04, 02:25 PM

" 'last known good' registry " according to whom? You think Windows XP checked whether or not Dialup was active before it selected a registry to restore? You can undo restoring a registry from backup so I think it's worth a try, especially since you don't seem to actually know (neither do I) exactly what was restored when you booted "last known good settings". I would suggest manually restoring more than one registry backup to see if any of the more recent ones can fix your problems. Just an idea, it's worth five minutes of your time.

jan_hut

06-15-04, 02:25 PM

hehe well I used the only backup registry that I had (I live on the edge and only keep one with system restore set to a minimum..lol) I got one step further and the problem seems to be that "remote connection manager" is not started as a service. Now when I try to start the service I get an "error 5 access denied". What exactly is preventing the service from starting I haven't been able to find out yet.

CHE

06-15-04, 02:25 PM

You have exceeded my limitted expertise <img src="i/expressions/face-icon-small-tongue.gif" border="0"> Especially since I have never usd XP <img src="i/expressions/face-icon-small-wink.gif" border="0">

jan_hut

06-15-04, 02:25 PM

well it doesn't seem to be a security issue....I applied a standard template and it's still now working. The eventlog says "unable to create buffers, Access Denied, Restart the computer".

jan_hut

06-15-04, 02:25 PM

oooh by the way it was this specific tweak that caused the lock-up in the first place. no idea why

jan_hut

06-15-04, 02:25 PM

update: I know why....apparently the beta SP1 (not sure which built) caused both the infinite loop when changing the secondlevelcache and the access denied error. I uninstalled SP1 and all works fine now. Guess it's better to wait for the final release <img src="i/expressions/face-icon-small-smile.gif" border="0">

JoshDaMan

06-15-04, 02:25 PM

I have an Intel Celeron 1.2 Ghz and windows WP what is my cache size?

Serialthriller

06-15-04, 02:25 PM

another question, I'm running Xp Professional, and dual Pentium 3 slot1 coppermine 1ghz chips. each has a 256 on die L2 cache...now....do i set secondleveldatacache to 256, 512, or what?

ADRAMELK

06-15-04, 02:25 PM

Malc, Screw the M$ knowledge base. The L2 cache is onboard the processor, I dont care what anyone else says. A 2MB L2 cache is years away, why the knowledge base even threw that in there is beyond me. Perhaps M$ has their heads so far up their asses about not realizing this before releaseing XP they are making ************************ up. Bobbyism, Computers use hex numbers because the system is base 16, which is optimised for architecture. The registry changed your base 10 number (256) to a base 16 number (100). 256b=100h Josh, Celerons have 128k L2. SerialThriller, Thats a damm good question, id say 256 though.

GNXtreme

06-15-04, 02:25 PM

Adremelk once again WOWS the crowd....****applause****

shez

06-15-04, 02:25 PM

LOL ADramelk you have a great poetic way of showing your love for microsoft, though i am sure your kind of love you have towards MS is world shared,

ADRAMELK

06-15-04, 02:25 PM

Thanks guys... But seriousally... dont listen to me, Im usually fully of crap. I make stuff up as I go along. plus I was drinking makers mark all day that day... <img src="i/expressions/face-icon-small-happy.gif" border="0">

WDB

06-15-04, 02:25 PM

I recall some server CPUs having large 2mb cache, as well as a few SS7 boards with a 2mb cache (I have one). Would the reg hack help with those?

Silence

06-15-04, 02:25 PM

Hey guys, well i have an Pentium 4 1.49GHz and don't know what value i should put for the L2 cache, if anybody knows plz tell me....<img src="i/expressions/face-icon-small-smile.gif" border="0">

Juan

06-15-04, 02:25 PM

I would say 256k because they didn't start the 512 til 1.6Ghz

Silence

06-15-04, 02:25 PM

thnxs Juan

Juan

06-15-04, 02:25 PM

No problem

Ace123

06-15-04, 02:25 PM

umm juan wouldnt adding 256 2700 memory be usless since you have a bunch of 2100 memory

Ace123

06-15-04, 02:25 PM

Im working on this project... its sorta weird but I enjoy doing it. i put an asus a7n266-vm motherboard into an old hp pavilion 6635 case with an amd athlon xp1800+ processor and 256 megs of elixer memory. now everything fits with a few modifications and im using the computer to write this... however im a littler affraid the powersupply is a smidge inadaquate.. the powersupply says 100watts cpontinuous power. seem a little too little. everything seems to run fine.. infact great.. but my 12v is at 11.4 and my 5v is at 4.945, my 3.3 is at 3.36 however wich is a little over and my vcore is are 1.776.... is this all enough or should a get a new powersupply and do they make one to fit this machine?

jan_hut

06-15-04, 02:25 PM

100 watts continuous is a bit low though the usual ratings you see (300 Watts, 430 Watts etc.) are actually peaks, not continuous.

Ace123

06-15-04, 02:25 PM

the computer is acctually running quite well... i added a bunch of cooling cut a hole in the side of ths case and running a 32 cfm fan with a couple blue leds blinking looks pretty sharp and an exuast blower at 42 cfm... no probles like resets or nothing. lots of modifying the case to get it all to fit though.. harder than an itx..

Ambian

06-15-04, 02:25 PM

AFAIK the original Athalons have 512K L2 Cache @ 1/2 speed, so a 750MHz should have 512k, right?

Colin

06-15-04, 02:25 PM

<< AFAIK the original Athalons have 512K L2 Cache @ 1/2 speed, so a 750MHz should have 512k, right? >> That's both right and wrong. At higher speeds AMD slowed down the L2 cache further because they couldn't get fast enough SRAM.

filip69692000

06-15-04, 02:25 PM

i have the athlon XP 1900+ at 1.6 ghz whats my cache size?

Colin

06-15-04, 02:25 PM

filip69692000 your cache size is 256KB...

NuTrybe

06-15-04, 02:25 PM

what's the L2 cache size for a PII 400?

Ace

06-15-04, 02:25 PM

and the cache for a amd athlon xp 1600 thx

pad07

06-15-04, 02:25 PM

little problem trying to get this tip to work can't find hkey_local_machine, System, CurrentControlSet, Session Manager i can't find this tab "Session Manager" i'm running win2k with a PIII 550mhz slot-1 BTW my processor L2 cache size is 256kb right?

pad07

06-15-04, 02:25 PM

Very confussing i didn't found memory management with your path but i kept looking around and found it here hkey_local_machine, System, CurrentControlSet, Control, Session Manager, Memory Management and found the DWORD SecondLevelDataCache with the next hexadecimal value "0" of course without quotes should i use this path?

Avid6eek

06-15-04, 02:25 PM

<< and the cache for a amd athlon xp 1600thx >> The L2 cache on your processor, whether it's a Palamino or TBred, is 256kb

Avid6eek

06-15-04, 02:25 PM

<< Very confussing i didn't found memory management with your path but i kept looking around and found it here hkey_local_machine, System, CurrentControlSet, Control, Session Manager, Memory Management and found the DWORD SecondLevelDataCache with the next hexadecimal value "0" of course without quotes should i use this path? >> That's the one. Just change it to the value of your L2 Cache.

timberlandman420

06-15-04, 02:25 PM

Thanks alot Colin i noticed an instant difference in speed when i opened up internet explorer and various games. AMD Athlon XP 1700+ K7S5A Pro Board 512 PC2100 DDR 32 Meg Viper V770 Video Sound Blaster Live 4 Channel 48x Samsung CD-ROM 32x10x40 Lite-On CD R/W 120 GB Maxtor 2 MB Buffer 18.3 GB Western Digital Ultra SCSI/2 4.3 GB Seagate Barracuda Ultra SCSI/2 15 GB Maxtor Adaptec SCSI Controller 5 Fans Unknown case with 420 Watt PS (looks good tho!) Windows XP Pro

Ace

06-15-04, 02:25 PM

Thanks Shiznit

CompSnake

06-15-04, 02:25 PM

<< 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. >> what about for win 98?

jackyw87

06-15-04, 02:26 PM

Ok, my directory for the Memory Management is: hkey_local_machine, System, CurrentControlSet, Control, Session Manager, Memory Management. In the Memory Management, I can't find secondleveldatacache, but I see LargeSystemCache-- Is that it?? Is there any other way? I'm running with AMD XP and Win XP Pro.

dark3xe

06-15-04, 02:26 PM

hey can u guys out ther help me? I have 5 comps at home and i wanna to know the cache of my processors.... 1. AMD Athlon TBird 900Mhz 2. AMD Athlon TBird 1.4Ghz 3. AMD Athlon XP 1600+ 4. AMD Athlon XP 2000+ 5. Intel Pentium 3 (500 MHz)

jackyw87

06-15-04, 02:26 PM

Can SOMEONE please answer me? <img src="i/expressions/face-icon-small-happy.gif" border="0">

Ghost

06-15-04, 02:26 PM

yea you have to right click in the right pane go to new dword value and then copy past this with out the quotes " SecondLevelDataCache " then after you do that just click any where in the window so it will set what you named it ,,then double click it chose decimal and add the value of your L2 cache ,click ok and reboot

cheezin8ter

06-15-04, 02:26 PM

Go to <a target=new class=ftalternatingbarlinklarge href="http://www.powerleap.com/consumer/upgradefinder.htm">http://www.powerleap.com/consumer/upgradefinder.htm</a> to find out your level 2 cache.

jackyw87

06-15-04, 02:26 PM

Sweet, thanks Ghost. <img src="i/expressions/face-icon-small-happy.gif" border="0">

meeeee2

06-15-04, 02:26 PM

Hey Colin. I tried some of your tips. and now my CPU is being used FULL TIME! the system Idle process is useless now. it takes internet explorer 3 -5 minutes to open, I can't even open the Windows XP Task manager. Could it be your tips or just my computer being a jackass to me?

Ghost

06-15-04, 02:26 PM

i use a lot of tweaks here my self ,,what tweaks do you think that you done mace your rig mess up ?? how much memory are you running ?

Winger

06-15-04, 02:26 PM

<img src="i/expressions/face-icon-small-shocked.gif" border="0"> People MUST have a basic working knowlegde before tweaking (especially with regs).

Lugnut25

06-15-04, 02:26 PM

Hey Colin, I'm new here. I'm confused with change from Hexidecimal to Decimal . I checked and mine has no values set I sure would like to set mine up :-) Thanks Colin

Lugnut25

06-15-04, 02:26 PM

Hey Colin Never mind I figured it out on my own

CaPri

06-15-04, 02:26 PM

Maybe it's a bit late, but for those who are still tryin' to find out how much L2 cache the Cpu has, here's a little program called Cpu-Z. <a target=new class=ftalternatingbarlinklarge href="http://users.pandora.be/mycapri/cpu-z-114.zip">cpu-z-114.zip</a>

mrbios

06-15-04, 02:26 PM

helo every1 i avent talked ere in a while what would you do if you where changing processors from an athlonXP1800 wiv 256 to a barton wiv 512k?? would it be ok to not btoher changing it till after you put ur neew chip in? or would i have to do this before putting it in? or even put it bak to 0 ALSO should it be decimal or hexidecimal?

Zefram

06-15-04, 02:26 PM

hey mrbios, why don't you find a 256bit ATi Radeon 9500 Pro (discontinued production)and flashed it to ATi Radeon 9700Pro? Use RivaTuner and load the Soft9x00.w2k file, then flashed it. Gotta give you graphic card same as 9700Pro, only a bit cheaper <img src="i/expressions/face-icon-small-smile.gif" border="0"> If i had a Pentium 4 Extreme Edition with 2MB L3 cache, how am i going to tell the OS how to use the freakin cache? or just tell it to use the 512 L2 cache? Do you have to add any new reg keys?<img src="i/expressions/face-icon-small-confused.gif" border="0">

JoeMac

06-15-04, 02:26 PM

Thanks worked like a champ!

Doc Timbo

08-15-04, 03:01 PM

didnt the EE edition have 1meg L2 cache?
I was thinking that the 2.0a P4 that was mentioned earlier was a williamette (256k L2) cus when i got my 1.5Ghz williamette the fastest P4 was a 2.0Ghz

LBJGH

09-08-04, 03:38 PM

I just tried this tip with my A64 that has a 1mb cache ... didn't notice any difference...

Crax

09-29-04, 02:57 PM

So I was just looking through some stuff and figured Id check through some of these tips again. Decided Id read all the way through this thread. Then I got to thinkin, hmmm ever since I upgraded to SP2 I havnt looked at my registry tweaks. I looked and it had reset my L2cache back lol. Im so excited I cant wait to see if it gives me some boost to my benchmarks :) Also for some reason I think I only had it set at 256 before :confused: Then I was like, wait a sec... what the heck was I thinking? I feel like noob :o

Ginsu543

09-29-04, 05:28 PM

Does this tweak work for Win 98SE?

gokusimpson

09-30-04, 01:13 AM

didnt the EE edition have 1meg L2 cache?
I was thinking that the 2.0a P4 that was mentioned earlier was a williamette (256k L2) cus when i got my 1.5Ghz williamette the fastest P4 was a 2.0Ghz

No. The E has a 1 mb L2. The EE has 2 mb L3.
E is a pressie core.
EE is the Extreme Edition (Extremely Expensive Edition)

braindead

10-07-04, 11:56 PM

I have my barton xp2600 with 512 L2 cache running up to it's rated speed after I did this tweak,it was always a tad slow before,thanks colin!

GonnaGoPostal

10-30-04, 07:26 PM

Is there anyway to help boost mem mgmt under windows for a L3 cache?

Ginsu543

11-18-04, 03:20 PM

Man, this tweak really helped increase my system performance. Before the tweak, I was getting 7322 / 6594 / 2080 on PCMark02. After the tweak, I got 7400/ 6622 / 2162. Nice boost all the way around on cpu / ram / hdd. Thanks for the tip!

grafton26

11-20-04, 08:29 PM

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. 

Hey colin here is an update for those that aren't aware of the difference, AMD ATHLON XP 3000+ has a 512KB L2 cache (Barton Core ) ;)

Ginsu543

11-20-04, 08:41 PM

When in doubt, you can always use Cpu-Z to find out how much L2 cache you have.

Wolfgang

12-20-04, 03:28 AM

Why would microsoft not do this? Can I see a bench of before and after?

cincy

01-05-05, 05:55 PM

Colin

Thanks!

Cincy

Freakker

01-05-05, 07:59 PM

Why would microsoft not do this? Can I see a bench of before and after?

there is a PCMark02 benchmark above.

newtech

03-14-05, 11:50 AM

;) I really appreciated this tweak. I'm telling everyone I think can handle the instructions. I have been recomending downloading amdcpuinfo.exe from AMD and another similar program from Intel to remove all doubt about "what is my L2 Cache". This is a good place to learn I'm glad I joined!

pman

03-24-05, 03:25 PM

yahooadam

11-14-05, 01:35 PM

holy crap did this make a difference

outlook used to take 10-15 seconds to load, now its instant :o

Skorp

11-14-05, 01:37 PM

Hmm. I'll report back on the diffrence it makes to a multicore system here. I'm wondering if 512KB is the correct value, being as there are two lots of L2 cache.

EDIT: Ye GODS! That took 10 seconds to test. 3DSMax started up about ten times faster than usual. Unbelievable...

dog2525

11-14-05, 04:00 PM

for people who do not know their L2 use. Cpu-z.
http://www.cpuid.org/cpuz.php

slaw_dawg

11-14-05, 11:16 PM

boosted my 3dmark03 score 200+ points... well done collin :D

EDIT:
works on WinXp x64 pro too btw

LBJGH

11-14-05, 11:19 PM

I just set the L2 to 1024 on my x2 4200+ (2x512). I'll post back with results. :confused:

yahooadam

11-15-05, 04:20 AM

I just set the L2 to 1024 on my x2 4200+ (2x512). I'll post back with results. :confused:
i would have thought 1024 is the logical amount as thats how much you have

irrelevant if its on seperate cores ...

Skorp

11-15-05, 10:41 AM

i would have thought 1024 is the logical amount as thats how much you have

irrelevant if its on seperate cores ...

Thats how much L2 I have, yes, but it isnt a shared L2. Hence my confuzzlement. Data can be passed between the L2 caches, but they cant be treated as one lump of cache.

yahooadam

11-15-05, 12:48 PM

Thats how much L2 I have, yes, but it isnt a shared L2. Hence my confuzzlement. Data can be passed between the L2 caches, but they cant be treated as one lump of cache.
winblows should distibute tasks between cores though ....

so windows should be able to use the whole 1mb of cache

however i dunno the answer either ....