Windows 7 Micro stutter Fix - Core Parking

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.

 

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

 

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.

 

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!

 

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

 

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:

 

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...

 

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.?.

 

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?

 

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%...

 

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

 

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.

 

This is a great post. Thanks!

 

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!

 

"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.

 

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

 

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

 

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?

 

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.

 

SAME HERE! I should run some benches.