[XtremeHardware.It] Core Parking on Windows 7 - Page 5

If the score didn't change, CPU load can't have changed.

Try WinRAR, it's the only test that really seems to show a large enough difference to be sure it's working. If WinRAR's bench doesn't show a sizeable difference, the setting probably isn't doing any thing on your system (or mine), which would add weight to my hypothesis that the HT issue with the core parking feature was probably solved in some update a while ago.

Yes.

Without HT, there is nothing for the core parking settings to do on Windows 7.

http://msdn.microsoft.com/en-us/windows/hardware/gg566941
Edited by Blameless - 12/7/11 at 4:44am

Ok, it works. 7zip benchmark went from ~16k MIPS to ~22k MIPS. Nice.
Edited by Pillz Here - 12/7/11 at 4:57am

The Key for Processor Power Managment is.


[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00]

DO NOT CHANGE ANY KEY Exept Attributes in the Subkeys

Setting Attributes = 1 Hides it in the Powermanagment tab of the Systemcontrolcenter.

Setting it to 0 or 2 Shows it.

Now u can use the Powermangment App of the Controlcenter and it will show the new activated settings.

Windows Powermanagment settings change on the Fly there is no need to reboot, as soon u hit OK they are active.

What is suggested in OP´s Thread Changeing 64 HEX to 0 does this it CHANGES the Range 0-100% to 0-0% (64HEX=100) this completly ****s up the maths cause there is no range between 0 to 0, this damn tweak sites hardly get stuff right

And yes not even Microsoft gets it right anyway an example i have to deactivate Coreparking on my I5 4 Core to actually use it, Windows 8 fixes this it activates it on my I5.

0cc5b647-c1df-4637-891a-dec35c318583 Subkey Sets up the minimum allowed unparked Cores setting this to 100% leaves all cores uparked, if u have a 8 core setting it to 25% will park 6 Cores 50% parks 4 cores 75% 2 Cores etc.



This is how it´s done right.

That is quite a difference.

What other power management settings is your system using, and when is the last time you updated Windows?

Trying to find out what makes it work for some, but not others.

I'd actually have to revert back to get a completely accurate score. HT was disabled and the benchmark was reading around 14.7k MIPS so I'm assuming with HT enabled it would be around 16k (with a 920 @ 3.8ghz - correct me if I'm wrong).

I'm on the high performance power plan and C1E/Speedstep disabled. I check for updates at least once a day usually - my Windows 7 is fully up to date.

Does work , i went from 6.7 to 7.3 in cinebench with my i7 870 @ 4.2Ghz i only ever got 7.2 at 4.4Ghz .. cool ! wish i knew about this earlier

awsome , so what else do we advantage from this ? cant somebody explain core parking more thoroughy because i hardly understand ..

If u use C-States The CPU switches off Voltage to Core Parts this is done CPU internal Usually the OS does not know when this is done so in the worst case the PM just ordererd the CPU to switch to a deeper C-state and a few microseconds later the OS Schedules work on this just Sleeping core now the core has to go from off to Fully runing this costs more energy then if it´s working normally (overvoltage ? usually lightbulbs blow up if u switch the light on).

To stop this they invented Coreparking, Coreparking moves all threads to one CPU core as long the given CPU Core is below a given usage % now all Threads are Schueduled on that active core leaveing all others in a Parked state so there is no need for Parked cores to Change the C-State from off to executing, so with coreparking u lower the amount of C-state switches either the core is longer on or longer off so haveing less Switch phases each switch phase has a latency aswell example changeing a core from C3 to C0 takes 17 Microseconds C1 to C0 about 3 Microseconds etc.

Third is Cache flush if u keep one thread on the same Core all the time the Cache is there aswell if u move a Thread to a new core u have to move the Cache aswell and empty the old Cache this takes time aswell.

So usually Coreparking is there to improve Performance and lower Power consumption. But it doesn´t work out like that with Hyperthreading the os cant know if it´s a real or a virtual core, also the logic is quite simple i takes core 0 then unparks core 1 etc. Now with HT 0 is the Real Core and 1 the HT Core thats where the problem is.

To work around this Intel had to Change the core numbering 0-3 Real 4-8 HT cores or Microsoft relise that and only Park every 2nd core Switching off the HT Cores 1st and then the Real ones. A HT Core only has about 40% of the Performance a Real core offers so the Real ones had to be used 1st guess thats where the performance loss is.

Or maybe setting Min. unparked cores to 50% allready is a small work around to the Performance hit with HT. I dont have HT so i cant test it out :/
Edited by erniv2 - 12/7/11 at 6:29am

Interesting, on my system "Processor performance core parking min cores" was set to 10% by default. I never tweaked this setting in the past mind you, nor do I use any utilities that tweak performance.

Has anyone else had this set to 10% by default?

wow nice explanation , was that c&p or do you know all of that lol ? thanks