There is an Intel paper off Tom's Hardware that discusses why core parking may be an issue. There aren't many programs that need very low latency real time processing of data like a DAW.  The way Intel achieves over-clocking is by turning off cores for several reasons (heat, leakage). With a DAW we need consistently fast and steady processing. I wouldn't have believed it until I read the Intel tech bulletin. It's amazing the old problems they are still solving with brilliant techniques. It doesn't hurt anything to turn off core parking except your light bill a tiny amount.

I found 2 instances of "" 0cc5b647-c1df-4637-891a-dec35c318583" in my registry & changed the values to "0".
After that, I had a problem that I thought might be related & decided to enter a value of "64".
The registry no longer has any reference to "" 0cc5b647-c1df-4637-891a-dec35c318583" in it!

Any ideas?
Thanks in advance,
Mick

So much for follow up!...

Supaboid

This thread, especially mad_man's post, is a very good write-up regarding the issue and the solution given here that makes use of 7's power plans is great - true set and forget. 

6) Go to the Advanced settings, you will see the "processor performance core parking min cores" parameter. You'll see the default values of 10%. Change them to 0% for either AC, DC or both. 

Unfortunately a typo snuck in there - readers will want to set 100% in this step. It's very easy to verify what setting does what if you want to be sure: 

- Open the task manager, go to the Performance tab and click on the Resource Monitor button. 
- In Resource Monitor, go to the CPU tab. On the left handside, choose 'Small' from the Views drop-down menu so that you can easily see all cores even if you're on a HT-enabled 6-core machine. Parked CPUS/threads will be clearly titled 'Parked'. 

Now change the "Processor Performance Core Parking Min Cores" setting in your power plan that you created as per mad_man's instructions. If your computer is idle, you will see the change in 'Parked' CPUs one second after clicking 'Apply' in the power plan advanced settings window. 0% will cause as many Cores/Threads to be parked as the CPU will allow. 100% will keep all Cores/Threads unparked all the time. 

THANK YOU SOOOOOO MUCH.  I was banging my head against a wall trying to figure out why, even after trying every method to turn core parking off it still stayed on (changed the reg keys max value thing and turned off speedstep in bios) 
I finally went in and deleted the "attribute" line in the registry as mad_man stated and saw the option in my power settings and put the values to 0%- but like you said supaboid (and i should have read the little info that pops up when you mouse over the power setting) it wasn't keeping the cores from parking. 
Saw the quoted red text in your post and some how had missed it before; followed your steps (opened resource manager and set % to 100, hit apply to see it happen in real time) and BOOM all cores un-parked!!
Thank you thank you thank you mad_man and Supaboid!!!!!!!!!!!!!!!!

(split message in to two because I 1) couldn't delete first post and 2) couldn't find a way to change the message so that it wasn't all "quoted"- even the stuff i wrote looked like it was part of Supaboid's post)

Some things I'd like to add here:

All stock power-profiles coming with Windows 7 leave 50% cores running, which means that each core will only have its hyperthreading processor being parked. It doesn't matter if "Processor performance core parking min cores" is set to 10% by default, because "Processor performance core parking core override" overrides this setting and is set to "enabled" in all those profiles.

You can check that yourself by either Resource Monitor (CPU tab) or Performance Monitor (Processor *Information* -> Parking Status).

-*-

Disabling Core Parking only means to keep Windows from shifting non affinity threads to different cores. It does not keep the CPU cores from entering CPU C-states C3/6/7! All of these three states are considered "disabled" cores by Turbo Boost.

Core Parking can be beneficial when you are running low CPU load. First it keeps the load running on a more active core, which in turn will not as easily enter deep (slower to wake up from) C-states C3/6/7, it's too busy for that. Second it will allow other cores to enter deep C-states and thus allow Turbo Boost on iX CPUs to increase the clock-rate of the remaining active cores.

Windows' default policy to keep 50% cores enabled obviously never allows a CPU to reach it's highest Turbo Boost bin btw. So when an i7 Quad 2.3 is listed as reaching a maximum of 3400 mHz, it will never see that clock, but only 3300 mHz max (50% cores disabled).

-*-

To make "hidden" power-profile options visible and editable via GUI you do not have to delete the "Attribute" value! Just set it to "0".

I think it's better to turn that stuff off in bios.

On a Dell i7 bios it's called

Speedstep Tech
Turbo mode Tech disable dynamic overclocking
C-state Tech disable parking of cores 2-4

Made my W7 x64 run much smoother.

Taskmanager will show 8 cores if HT is enabled.

Why disable power-saving options permanently when you can switch it on the fly? Some people like to do web-surfing in between and like to keep their homes cool instead of burning away idle cycles. :P

First off, let me give a kudos to mad_man for describing the often confused new CPU core parking pretty well. It is an energy saving method primarily used for servers and mobile devices (laptops, netbooks, etc..). However, it can be used on desktop systems, but it is not usually desirable, and I've not seen a case where it is enabled by default on a non-server Windows Vista/2008R2+ install. Note I already mentioned it is enabled by default on laptops ;p.


In theory, it can be configured via the powercfg.exe command line utility, instead of using manual registry edits. I wrote about it here: http://processlasso.blogspot.com/2011/06/cpu-parking-revisited.html . However, this CPU feature is not listed in the Power Profile options, and is handled .. oddly. Therefore, I did more testing, and I later came to wonder if this was reliable. I need to run more tests to be sure, and perhaps update or delete that old post from June. It seems that they prefer everyone just let Windows make the decision on this one, lol.


The largest issue with core parking is that, like frequency scaling, the 'scale up' time is underestimated. Most CPU activity occurs during brief micro-bursts, and this is where you want your speed at. Even if you are only using 1% of your CPU capacity per second, that does not mean 99% is unused - it means that the CPU was in use 1% of that second, and how fast it executed the code using that 1% of CPU time is what matters. So, when a burst occurs, it is often over before the OS has a chance to scale the frequency of a CPU up, or disable core parking. 

Timur

Why disable power-saving options permanently when you can switch it on the fly? Some people like to do web-surfing in between and like to keep their homes cool instead of burning away idle cycles. :P 

This is why I added to Process Lasso the new Energy Saver function. It drops the power profile down after you go idle for X seconds, then right back up when you return. That way, you can run at High Performance all the time (for instance), but have it drop back down seconds after you go idle. Of course, 'default' or 'application invoked' power profiles is something Process Lasso also does. I won't post a link to Process Lasso itself here, else this post might be considered spam. However, the Energy Saver is one of its many free forever features, and it has no timed nag screen and no bundled BS.

So I've read this thread, and it seems unclear if I should change in the power options the core parking setting. My quad core is really only utilizing two cores and just wanted to get a clear answer on if i should set the values to 0.