What is CPU Unparking?

[orangecat]

I heard somewhere that if you unpark your CPU cores it makes them faster or something but I don't know what it does or even if it makes a difference. I have this small application called UnparkCPU but who knows if it even works.

 

http://www.coderbag.com/Programming-C/Disable-CPU-Core-Parking-Utility

[Morpheus]

following!

[SkilledRebuilds]

ParkControl is better, no restarts needed, realtime display of how its working when your using it... & you can Set it up for different power profiles.

^Look into it.

Yes it helps, but its gain is so small you would not notice much in any application..

 

The real reason it helps is when Games/Programs have issues themselves,....and do not use all threads and suffer when they do not open up the rest of the CPU's, and if only CPU1&2 are being used, CPU3,4,5,6,7,8 can be turned off (Saving power) Which is great for laptops. I disable it on every desktop I work on. I'd rather having all Cores open & available at all times without any switching happening in the background.

[Kamina]

I think it's only an issue on W7. 

 

On W8.1 when I put the power saving features to high performance, my cores become manually unparked. The performance gains? I can't even notice it. They unpark themselves when they are needed.

[deathjester]

I think it's only an issue on W7. 

 

On W8.1 when I put the power saving features to high performance, my cores become manually unparked. The performance gains? I can't even notice it. They unpark themselves when they are needed.

 

^ This. Win 7 and I7, big core AMD chip. Unpark cores. On Win 8.1 don't bother. It does nothing. Win 7 core parking is bugged on games like BF4, Planetside 2 (8 core games).  

 

Not to be confused with Windows power management settings or laptop proprietary programs that throttle the chip to save battery life. Make sure max is set to 100 under advanced power savings. Min? 5 percent is fine. The min doesn't matter the max does. You want the min low. Like on this forum? My 4770k is chilling at 800 mhz. and sub 30C. That is what it is supposed to do. .  Desktops should be at 100 max automatically. If temps are already bad on laptops which run notoriously too hot? Don't touch it. 

[Faa]

I think it's only an issue on W7. 

 

On W8.1 when I put the power saving features to high performance, my cores become manually unparked. The performance gains? I can't even notice it. They unpark themselves when they are needed.

You have hardware core parking and software core parking. Windows just assigns threads to your cores, if it has the feeling to move the thread to somewhere else with a much higher load, the previous core would be free and one of the C states will turn it off. Anyways most games have like in total 40 threads with 2-4 threads being the engine so the engine can effictively use 2-4 cores and nothing more while all other threads are stupid & small they can be moved to the engine's core without a performance loss. Turning core parking off never made any difference for me in windows 7.

If you'd have a simple 3770 non K, you'd have in some situations with core parking enabled more single core performance since the typical working of Intel's turbo boost if the OS keeps a core disabled.

Also, if you switch your profile from balanced to high performance, you're disabling all C states because the min cpu speed goes from 5 to 100% -> so no core parking at all.

As you see (balanced profile), if I change it to 100% the cpu goes immediately from 1200MHz to 4500MHz.

AMD's new bulldozer kinda had some issues:

 

Another purpose of this article was to tackle the problem surrounding Bulldozer and its derivatives, such as Piledriver and thus all Trinity and Richland APUs.  The architecture is such that Windows 7, by default, does not accurately assign new threads to new modules – the ‘freshly installed’ stance is to double up on threads per module before moving to the next.  By installing a pair of Windows Updates (which do not show in Windows Update automatically), we get an effect called ‘core parking’, which assigns the first series of threads each to its own module, giving it access to a pair of INT and an FP unit, rather than having pairs of threads competing for the prize.  This affects variable threaded loading the most, particularly from 2 to 2N-2 threads where N is the number of modules in the CPU (thus 2 to 6 threads in an FX-8150).  It should come as no surprise that games fall into this category, so we want to test with and without the entire core parking features in our benchmarks."