Unlock Core Parking

[FordGT90Concept]

This program is a rethink on Set Core Parking Max in that it assumes the best way to control these settings is by using Windows' Power Options settings.

First, simply download and run UnlockCoreParking.exe (attached). If it doesn't seem to work correctly, try running as administrator. It should automatically open the Advanced Power Options dialog. Open Advanced Power Options manually if it doesn't by way of the Control Panel.

Second, select the Power Plan to configure via the combo box at the top.

Third, scroll down to "Processor power management" and expand it. Now expand "Processor performance core parking min cores." Change the Setting from 10% to 100% and apply. Core parking is now disabled for this power plan.

Spoiler: Source

Attributes DWORD 1 means hide the value in Power Options. I simply delete that key--the first is for min cores and the second is for max cores. The Process.Start opens Power Options and the ,,1 specifies to open Advanced.

using Microsoft.Win32;
using System;
using System.Diagnostics;

namespace UnlockCoreParking
{
  class Program
  {
    static void Main()
    {
      try { Registry.LocalMachine.OpenSubKey(@"SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\0cc5b647-c1df-4637-891a-dec35c318583", true).DeleteValue("Attributes"); }
      catch { }
      try { Registry.LocalMachine.OpenSubKey(@"SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\ea062031-0e34-4ff1-9b6d-eb1059334028", true).DeleteValue("Attributes"); }
      catch { }
      try { Process.Start("control", "powercfg.cpl,,1"); }
      catch { }
    }
  }
}

 

[Frick]

Didn't you make this already?

 

[FordGT90Concept]

The other program (link in OP) adjusts it for the current scheme. This one doesn't adjust anything beyond making the settings in Power Options visible.

 

[micropage7]

its interesting how simple thing could affect much

Core Parking is a sleep state (C6) supported by most newer x86 processors, and newer editions of Windows. Core Parking dynamically disables unused logical cores, turning them back on as the load on the CPU(s) increases. This technology is very similar to frequency scaling, in that it seeks to throttle the CPU's power consumption when idle.

Unfortunately, Window's default power profiles are far too aggressive when it comes to parking, especially on workstations. A large number of complex parameters control when a core is parked, so it is not hard to imagine these being less than ideal in many situations. And, Yes, core parking is enabled by default even in the High Performance power profile.

The core parking settings in Windows are exposed as parameters of power profiles. That means you can, for example, disable core parking for the High Performance profile, but leave it enabled for other profiles.

Real World Effects

It is difficult to precisely quantify the performance impact of core parking. However, my experience has been that disabling core parking on some CPUs, with some types of CPU loads, makes a real and substantial improvement in the fluidity of the OS. Fewer lags, stalls, freezes, etc...

Many other users have written to express that disabling core parking made a real and obvious difference.

I will also comment that disabling core parking for newer AMD processors seems to result in the largest performance improvement. I theorize that the recent changes to AMD processor architectures in Bulldozer+, where cores were paired together as 'modules' that share some computational resources, caused a situation where the Windows CPU scheduler is inefficiently managing these CPUs.

http://bitsum.com/about_cpu_core_parking.php

 

[Vario]

Easiest way is to disable C6 when in doubt!

 

[exodusprime1337]

I always disabled c6 in bios. I've never had them show up as parked.

 

[FordGT90Concept]

"A large number of complex parameters control when a core is parked"

The full list is in this post:
http://www.techpowerup.com/forums/threads/set-core-parking-max.194248/#post-3014206

This program only enables two: min cores which can be used to disable parking and max cores which can be used to force parking. The author of the post is referring to the dozens of other policies related to parking.

Two things to note:
1) Core parking only affects logical processors (e.g. hyper-threading and Bulldozer). If your processor only has physical cores, parking won't change anything.
2) These options really only exist in Windows Vista and 7. In Windows 8, Microsoft finally figured out that the High Performance power profile shouldn't have parking at all so just change to High Performance to disable it.

 

[qubit]

How can I tell if a core is parked? Is it with a flatlined graph in Task Manager? I just checked now and all "8" of my cores (4 core+HT) are showing activity

 

[Ed_1]

How can I tell if a core is parked? Is it with a flatlined graph in Task Manager? I just checked now and all "8" of my cores (4 core+HT) are showing activity

Bring up task-manager>performance tab , click resource monitor .
Now look on right side CPU graphs , if any are parked it will say in the graph .

 

[AsRock]

http://www.ghacks.net/2012/07/15/how-to-change-core-parking-states-in-windows/

 

[FordGT90Concept]

How can I tell if a core is parked? Is it with a flatlined graph in Task Manager? I just checked now and all "8" of my cores (4 core+HT) are showing activity

Here is an example of forcing Windows to park all cores (0% min, 0% max):

It's effectively the same as turning hyper-threading off on my Core i7 920.

 

[qubit]

Thanks for clarifying this people. None of my cores are parked.

I want peddle to the metal performance from my 2700K CPU, so I've got all the power saves turned off (which I expect might disable core parking). Note it's not overclocked at the moment, but it was previously, at 4.7GHz.

 

[_JP_]

Thank you for this wonderful tool! I was aware of the earlier version, but back then I was using a Core 2.
I was debating between disabling C6/Parking or applying the bulldozer hotfixes, since I got my APU.
I read that the hotfixes didn't always work and that some vishera-based installs didn't like them at all actually.
Parking be damned!
I still have C'n'Q, so I still get some power savings.

 

[FordGT90Concept]

I put the full source in the original post. It is literally only 20 lines of code.