# Windows 7 Micro stutter Fix -  Core Parking



## brandonwh64 (Feb 2, 2012)

Hi Everyone

I just found a great fix to stop win7 parking the cores when Idle.

This is an aggressive power saving approach which makes the system feel sluggish and underpowered..

*Who is affected*
It only applies to Windows 7 X64 and X32 and only in systems using more than 2 physical CPU's and/or more than 2 "logical" cores - ie: Core i7's.

*The Problem*
Core Parking is a feature of Windows 7 that is causing rare performance problems. I don't notice it on my home i7 / Win7 system but some people are getting microstutters and odd behavior in certain programs. Without the following " tweak" you may see CPU spiking in your programs and Windows Task Manager - some CPU cores will be "turned off" / "parked" depending on load and they will be dynamically turned on or off and dynamically loaded up or down as the system deems necessary - the scope for glitches / pops / clicks / dropouts etc.... in such an environment is simply enormous. To the best of my knowledge, there is no known "switch" to turn it off - no utility I am aware of to "tweak" it off.

*The Fix*
- Go to Regedit
- Select Edit > Find... and find this key: "Specify the minimum number of unparked cores/packages allowed (in percentage)."
- Within this key, there is a value called: " ValueMax " This value represents the % number of cores the system will park
- Change the value of " ValueMax" to 0 so that, it matches " ValueMin "
- You will have to find the key a few times and repeat the process for each time it is found - the number of instances will depend on the number of power profiles in your system. To do this go back up to Edit > Find Next. (I had 3 instances of this key in my registry.)
- Do a full shutdown and power-off and cold-re-start.

This seems to work better.

SOURCE

Thanks guys in the BF3 clubhouse.


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## Sasqui (Feb 2, 2012)

Cool tip.  Surprised no BIOS exposes that setting, or prhaps it does in a different way?


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## brandonwh64 (Feb 2, 2012)

Sasqui said:


> Cool tip.  Surprised no BIOS exposes that setting, or prhaps it does in a different way?



Its something windows 7 does to save some energy. This fix has been known to help anyone with HT shuttering issues in BF3


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## Sasqui (Feb 2, 2012)

brandonwh64 said:


> Its something windows 7 does to save some energy. This fix has been known to help anyone with HT shuttering issues in BF3



Yes, I knew that part, but there's a hardware/software layer that allows Win7 to do this, and my assumption is it's talking through the BIOS.  Much like the power saving modes of old.


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## cadaveca (Feb 2, 2012)

I made the changes, will check it out this afternoon.

First thing to report is that it did not affect idle temps at all.


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## brandonwh64 (Feb 2, 2012)

cadaveca said:


> I made the changes, will check it out this afternoon.
> 
> First thing to report is that it did not affect idle temps at all.



Nice! Please let us know how it works out for you!


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## _ALB_R3D X (Feb 2, 2012)

Same here...Temps are normal
Gonna try BF3 in a few minutes


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## johnspack (Feb 2, 2012)

Just tried this myself with winrar,  and it does indeed increase performance by a fair bit.  However there is an easier way,  just one reg mod and you can set it in power options!  0% is fully enabled,  and 100% and parking is fully disabled:


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## cadaveca (Feb 2, 2012)

johnspack said:


> Just tried this myself with winrar,  and it does indeed increase performance by a fair bit.  However there is an easier way,  just one reg mod and you can set it in power options!  0% is fully enabled,  and 100% and parking is fully disabled:
> http://img.techpowerup.org/120202/CorePark.png



I already tried to make those adjsutments, and "Core Parking" still seemed to be enabled, as the power plan here on my system didn't list core parking in the power options.


I wonder why it shows in yours? Weird...


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## DRDNA (Feb 2, 2012)

johnspack said:


> Just tried this myself with winrar,  and it does indeed increase performance by a fair bit.  However there is an easier way,  just one reg mod and you can set it in power options!  0% is fully enabled,  and 100% and parking is fully disabled:
> http://img.techpowerup.org/120202/CorePark.png



My power options did not change and I dont have any thing that looks like your screen shot.
Your screenie almost looks like windows is skinned to basic.?.


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## johnspack (Feb 2, 2012)

You just need to use the one reg mod I showed,  simply change the attribute from 1 to 0.  Then it will show up in advanced power options.


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## DRDNA (Feb 2, 2012)

johnspack said:


> You just need to use the one reg mod I showed,  simply change the attribute from 1 to 0.  Then it will show up in advanced power options.



where is advanced power options located?


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## johnspack (Feb 2, 2012)

Click "Change power settings"  then "Change advanced power settings".   Oh,  and I didn't need a reboot for any of this,  it worked right away.
Edit:  and yes,  I use classic interface,  with classicshell ect....


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## DRDNA (Feb 2, 2012)

johnspack said:


> Click "Change power settings"  then "Change advanced power settings".   Oh,  and I didn't need a reboot for any of this,  it worked right away.
> Edit:  and yes,  I use classic interface,  with classicshell ect....



Ahhh...okay...now I see it...lol

Mine was set at 10% originally. Now its at 100%...


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## johnspack (Feb 2, 2012)

Yep,  mine was at 10 as well,  when I put it to 100,  my winrar throughput went up a good 25%...


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## LAN_deRf_HA (Feb 2, 2012)

I did this awhile ago. Increased my gflops and did not increase power draw. What exactly is core parking supposed to accomplish because so far it just wastes performance.


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## Breathless (Feb 2, 2012)

This is a great post. Thanks!


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## DRDNA (Feb 2, 2012)

WOW right of the bat it has lowered my temp on my core 0 while folding with smp and v7!I always had core0 running a few degrees hotter but now its on par with all the rest of the cores! Hot damn nice!


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## cadaveca (Feb 2, 2012)

LAN_deRf_HA said:


> I did this awhile ago. Increased my gflops and did not increase power draw. What exactly is core parking supposed to accomplish because so far it just wastes performance.



"Core Parking" will fully disable and power down unused cores that support "Core Parking". It takes a moment or two to "wake" the "sleeping" core, which causes the performance loss. It will also shift workloads to active cores so that only the needed amount of cores are "woken" from the ultra-low-power state. Disabling Core Parking removes the Ultra-low power staes, having the cores ready for new work.


As far as I understand it, teh WIn7 kernel isn't able to fully support CoreParking right yet, so maybe that's why there is no differnce in idle states or power consumption. It's more than possible that the cores aren't actually "sleeping" in Win7, and are merely ignored for thread-dispatch.


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## _ALB_R3D X (Feb 2, 2012)

Maybe it's me but I'm feelin a bit of smoothness in BF3...anyone else tried yet?


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## LifeOnMars (Feb 2, 2012)

I'm crap with technobabble, would this encompass i5 2500k's as well?


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## cadaveca (Feb 2, 2012)

maybe, but it seems to be more for INtel CPUs with HT. Give it a try and let us know; it's easy to reverse.


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## LifeOnMars (Feb 2, 2012)

cadaveca said:


> maybe, but it seems to be more for INtel CPUs with HT. Give it a try and let us know; it's easy to reverse.



I'll try anything for a performance increase Whats the best indicator of any perfomance increase? Will it mean I can run Crysis? 

But seriously, which benchmark would show up any improvement?


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## cadaveca (Feb 2, 2012)

things that are more core-instensive, liek winrar and such, should show the largest gains, but I seem to be noticing an effect in nearly everything. It might be a placebo effect, but even IE seems to load up faster.


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## DRDNA (Feb 2, 2012)

SAME HERE! I should run some benches.


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## twilyth (Feb 2, 2012)

OP thanked.

Is it possible that I would notice a difference while running boinc on 8 threads in a 2600k?  My mouse was stuttering and with this change, the stuttering has decreased substantially.

Note:  I am running process lasso in the background, both before and after.

I changed every registry entry for "unparked" that had a value max parameter.  I noticed that in some cases this was already set to zero while the min was set to 05hex.  I reset the minimum to zero too.  After a reboot, it doesn't seem to have caused any problems - yet.


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## cadaveca (Feb 2, 2012)

twilyth said:


> OP thanked.
> 
> Is it possible that I would notice a difference while running boinc on 8 threads in a 2600k?  My mouse was stuttering and with this change, the stuttering has decreased substantially.
> 
> ...



Yes, because disabling Core Parking would have threads dispatched differently, and seemingly, more efficiently, there is something to be noticed in almost every task.

Theoretically speaking of course. I have no idea WTF is really going on.



odameyer said:


> Is this for the problem where a system will lock up completely and make a stuttering noise and have to be shut off manually?


not really. That'd be a crash, of the game or system or whatever, I dunno.


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## LAN_deRf_HA (Feb 2, 2012)

Funny, I seem to recall way back when people were saying their Phenom rigs seemed "smoother" than their 1366 i7s. Wonder if this is why. Maybe Intel should push MS for their own performance patch. Would have a rather quick turn around time given the simplicity of the change.


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## brandonwh64 (Feb 2, 2012)

Just tested out BF3 and it ran quite smoother! I may kick back up the video settings!


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## BlackZero (Feb 3, 2012)

Alternatively, open a text editor and add the following lines



> Windows Registry Editor Version 5.00
> 
> [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\0cc5b647-c1df-4637-891a-dec35c318583]
> "Attributes"=dword:00000000



save the file and then change the extension to *.reg. This will simply allow core parking to be made _visible_ in the power state settings in windows 7 x64. From there just change the min. power state/core parking setting to 100% to disable core parking, and back again if you want re-enable it.


ps.

I see johnspack already posted this.


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## EastCoasthandle (Feb 3, 2012)

I posted about this in another thread a few days ago.  For desktop users the general opinion is that you don't need to throttle or park cores.  However, if you don't noticed a difference at all then there is no real need to change it.  Which is why I suggested using winrar's benchmark program to see if you noticed any improvements or not.  

However, it appears that the greatest benefit in disabling Core Parking comes from running apps in a 2D environment (such as winrar, etc).  In 3D mode all cores are suppose to be available or non parked.  You can monitor this by using Resource Monitor's CPU tab to check the graphs on the right as well as the Max. Frequency in the upper right.


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## INSTG8R (Feb 3, 2012)

Tried BlackZero's method but no sign of Core Parking in Power Management. Even after a reboot.
Admittedly I had read about this before in similar forums as EastCoast had posted. Guys with DAW's were all over this Core Parking thing. 

I just dunno what I did wrong. Copied his text. Made it a Reg File and merged it. Said it was successful just no new option.

Edit: I did it Brandon's way anyway so whatever I didn't do right with the Reg file I did the "long" way.


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## johnspack (Feb 4, 2012)

INSTG8R,  if the reg file didn't work,  do what I did the first time I tried it,  and run regedit using admin privs,  and browse to that string,  and do it manually.  That's how I always test a reg setting to make sure it's applied.  If you set the attrib to 0,  and it stays,  and you can't see core parking in advanced power settings,  that's very strange!


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## yogurt_21 (Feb 10, 2012)

disabled it for mine, noticible improvement in desktop smoothness when switching between tasks, also got a slight bump in benches (3dmark11 physics before 23.6 after 23.9, combined after 30.34, before 30.13), nice. Intersting to show any improvment in benches since no cores should have been parked in that bench.


Thanks for the tip!

edit: the value max was 100 before but was currently at 64 when I changed it, what were everyone elses at?


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## ViperXTR (Feb 10, 2012)

i wonder how can this affect a dual core i3 >_>


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## mudkip (Feb 10, 2012)

So this is only for cpu's with HT ?


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## johnspack (Feb 10, 2012)

Yes,  this is mainly for cpus with HT.


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## ViperXTR (Feb 10, 2012)

might as well try it on my i3 2100 '__'


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## johnspack (Feb 10, 2012)

I believe it is also a help to cpus with 4t or more,  as some applications seem to allow core throttling/parking,  when they could actually be used.  The winrar benchmark clearly shows that,  and going from 4t to 6t makes a big difference.  Winrar seems to park on cpus with 6+t,  and unparking gives an instant 25%+ boost.  So I'm not sure this is any use for under 4 core cpus,  and is probably the most useful for i7 4c/8t and above.


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## Fitseries3 (Feb 10, 2012)

my lappy definitely boots faster and everything seems smoother so far. 

gonna try my desktop next. 

i5 2430m and i5 655k


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## erocker (Feb 10, 2012)

Anyone try this with a Bulldozer CPU?


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## cadaveca (Feb 10, 2012)

erocker said:


> Anyone try this with a Bulldozer CPU?



I think it'd be worse doing this. The whole M$ patch thing was to add this(core parking) to BD systems.


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## eidairaman1 (Feb 10, 2012)

johnspack said:


> Yes,  this is mainly for cpus with HT.



I say test it on AM2/AM3 CPUs aswell...


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## MxPhenom 216 (Feb 10, 2012)

brandonwh64 said:


> Hi Everyone
> 
> I just found a great fix to stop win7 parking the cores when Idle.
> 
> ...



yeah i did that line. and it seached and nothing came up.


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## t_ski (Mar 19, 2012)

Just noticed this.  I'm going to have to give this a try later


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## 95Viper (Apr 16, 2012)

Found this little utility, Disable CPU Core Parking Utility, at coder bag.

Tried it and it unparked my i7 cores.
It came up clean at VirusTotal

EDIT: I could have done manually, but I wanted to see if this utility worked.

Edit 2:
Here is another one from BitSum: CPU Parking (aka Core Parking, or CPU core parking)

This one I have not tried yet. I have to finish my coffee and have a smoke first.
So, try at your own risk.  Back up that reg.

Well, the one from BitSum tests clean and seems to work, albeit, with a little different interface than the one from coder bag.

I have not done any testing of differences in games/etc. as I am not a real big gamer and have not yet encountered the stutter problem, which, seems to affect some users.
Just tried to see if they park and un-park the cores.
So, test them for yourselves to see if parked or un-parked cores help your situation and don't forget to post your results/observations.

An observation, after un-parking:
I will say, since, I un-parked my cores the mouse seems not to have the (sometime) jitters and the menus/taskbar seems more fluid.  Could be me or could be a result of the un-parking.


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## qubit (Apr 16, 2012)

Thanks 95, that coderbag utility is very handy.


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## LifeOnMars (Jun 2, 2012)

Using windows 8 release preview, I have it on balanced power with an X4 B50 chip. It shows core parking !! I have had no issues however and gaming actually seems possibly smoother if anything but just thought I would put this out there


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## Drone (Jun 2, 2012)

Never heard of car ... core parking lol. Just tried the tip from the OP and nada happened/changed *sigh*


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## 3Hyuuuga (Jun 2, 2012)

What is core parking? sorry i'm newbie here..


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## LifeOnMars (Jun 2, 2012)

3Hyuuuga said:


> What is core parking? sorry i'm newbie here..



Yes you are, generally reading the OP will give you the information you need in a forum thread.


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## TheHunter (Jun 2, 2012)

Or use Bitsum's handy tweak, instead of going through the registry. Its the easiest tweak yet, just pinpoint which power plan you would like to modify and that's it.  

http://bitsum.com/about_cpu_core_parking.php

For example make a new power plan - name it CoreParking OFF and then pinpoint out this plan with bitsum's tweaker.



btw i used this procedure, so it really changed only for certain plan, not for all plans. But this was before i found out about this Bistum auto tweak. 
post #34 and post #39
http://forum.cakewalk.com/tm.aspx?&m=1861804&mpage=2


And it helps mostly by Audio production, it eliminates any unwanted delay/sound crackle, popups. Can help by games too, but i didnt really notice any difference.


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## jonathan1107 (Nov 18, 2014)

This "un-parking core" tweak worth it for someone like me using a i5 4690k (no HT) with main usage being GAMING ???


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