Disabling Parked Cores in Windows 7 using i7 Multi Processors

[Selkan 1]

There has been talk of the following tweak back in 2010, so I thought it might be worth repeating it here. Because I feel this is so relevant to FSX users, I am Posting a short Post over there suggesting they drop by here for a look. Firstly, I am getting quite a jump in FPS (in FSX), but the whole experience is much better; smoother, hardly a stutter.I do not take any credit for the following information, but have gleaned from different Posting across the Web. It always seems to me that very often people Posting here in general think others have the same knowledge as them, and therefore do not always give a very clear step by step when explaining how to do something. Forgive me if I am teaching some to suck on grandmothers eggs, but I am going to spell it out carefully, step by step for those not in the know.Firstly, this tweak is for those using Windows 7 and an i7 Multi CPU Processor. If you don't have that, then look away now! Lets first have a look at your Processor, and number of cores you have. Right click on your task bar, and select Task Manager. On the Performance Tab you will see a Tab reading Resource Monitor. Click on that and in the Window that comes up you will be able to see your CPU Cores on the right hand side. You probably have 4 Cores, plus a number of Cores that read 'Parked'. For me I had 4 main cores and a further 8 parked virtual cores.O.K. First step over; you have confirmed that you have some parked cores. I hear you saying straight away, why? In their wisdom, Microsoft decided to park a number of cores to save on energy used; fine for letter writing, internet use etc etc, but not for a demanding programme like FSX. This was and still is important if using a Laptop, where if running under battery power, consumption is very important. Most people running FSX are probably using Desk Top P.C.'s, and need all the power/performance they can get. FSX is very CPU dependant as we all know who use it. Now, in level flight, these parked virtual cores tend not to be used, but as you make turns and more scenery is introduced, your CPU has to work harder, and some of these parked cores will become unparked for short periods of time.So, it makes some sense to disable these parked cores, and have all (in my case 12) cores working all of the time.Here's how. 1. Firstly, using Notepad, open a blank file on your desktop and copy/paste this 'String' (I will refer to this as 'The String' as we go forward. [0cc5b647-c1df-4637-891a-dec35c318583] in to it. NOTE: just the letters/numbers - not brackets. Make sure you copy exactly, so copy/paste is best. So there is no confussion the first 0 in sequence is a zero not letter.2. Before closing Notepad, press File, save as, and give it a title - perhaps core parking, or similar. Save to Desktop.3. Now, open this Notepad file, and resize if necessary, but leave it open on your desktop for easy access.4. Click start in task bar, click RUN, and type 'regedit' (small case), click O.K. Registry Editor will open. Some may not have RUN available, if so write 'regedit' in the 'Search Box'. In the pane above you should see Registry.exe. Just double click on that, and the Registry will open.5. At the top of page, click 'Edit', follow down and click on 'Find'. A new Window will open and it will read 'Find What' Now, this is where you go back to your Notepad, copy 'The String', and Paste in the 'Find What' Window.6. There are four small boxes within the 'Find What' Window; if not already 'ticked' put a tick in each box, then click ' Find Next' which you will see next to 'The String' you just pasted in.7. Now, on the left hand side of the Registry Window you should have a load of Strings in a long list. Make sure the one we are dealing with is high lighted, and look to the right hand side. There you will see two headings we want to deal with: Min Value and Max Value.8. The Min Value will probably be set to 0 (zero), but the Max Value will probably read 64. This is the % that the virtual core can use, i.e. only 64%. Double click on the Max Value Heading, and in the Window that opens replace 64 with 0 (zero)9. Now in the Window with all those Strings, click file at the top but this time click on 'Find Next' - right at the bottom. If you have any other Strings with that same sequence that will come up, and can change the Max Value again.10. Repeat this unit no further Strings come up to be changed. For me it was only two.11. Now, this bits important. Close the Registry, and all other Windows, Close down your P.C., and remove power. Do NOT simply press 'restart'.12. Now, restart your P.C. and go back to task manger, resouce monitor, and you should see your cores are now unparked i.e. they will say nothing, which means they are now fully unparked.As a final note, if you are using an Anfinity Mask setting in your FSX.cfg, you should now deleat that entry. If for any reason you are not happy with the result of this tweak, you can reverse all, and place your setting back in your FSX.cfg.Most people wobble at the knee when it comes to changing the Registry, but doing the above slowly and careful should produce very good results.

[superglide17 11]

If you have Hyper Threading disabled in your BIOS, which is recommended when running FSX, you will not see any "parked cores".

[Illegitimi non carborundum 4]

SelkanVery well written :( - Most of us disable hyperthreading in the BIOS so we may not see all the cores that you are describing. Do you have HT turned on?On my i7 860 HT is turned off so I don't have any parked cores just 4 - cpu0 to cpu3.Most experts recommend turning Hyperthreading off as it can cause thread collisions in FSX and hence the dreaded stuttering plus a huge heat load on the cpu.Does this apply to all quad and six core cpu's ie from the earliest Qxxx quads to the latest SandyBridge 6's?Just a thought.PeterH

[Selkan 1]

Hi Peterhayes, thank you for your kind words. I have to be very honest here and say I don't know if my Hyperthreading in BIOS is on or off. I really am no expert in these matters, and can't therefore comment on the other items you mention. For me I have a large increase in performance, and things are nice and smooth; perhaps one or two minor stutters per whole flight over say a two hour period. I just wanted to share this tweak for the (I hope) benefit of all in general.Just a little more information for those that will follow this thread. I am using Nvidia Inspector, and Nvidia Drivers for a 480GTX, I believe presently 285.62. Many readers up until now will be using an External Frame Limiter (as I was), but using the latest N.I. build, plus 285.62 onwards, you will have a Frame Limiter within N.I. under the heading 'COMMON'. The recommendation is to set at 30fps (unlimited in FSX itself), but I have mine set at 60fps because I am using a TripleHeadToGo Unit, and find this setting gives me very good results. I think this one is for trial and error, and find the best spot for you.Just one last thought here about H.T. I came across a little program a while back that enabled just Four main cores, and turned off my virtual cores. I guess this would be the same as turning H.T. off in Bios. I am thinking therefore that my H.T. is turned on in BIOS, thus giving me twelve cores (four real and eight virtual - parked). By using the above tweak and setting all twelve cores to unparked, I appear to be getting better results.

Edited February 5, 2012 by Selkan

[Kosta 122]

Hi Peterhayes, thank you for your kind words. I have to be very honest here and say I don't know if my Hyperthreading in BIOS is on or off. I really am no expert in these matters, and can't therefore comment on the other items you mention. For me I have a large increase in performance, and things are nice and smooth; perhaps one or two minor stutters per whole flight over say a two hour period. I just wanted to share this tweak for the (I hope) benefit of all in general.

While I do quite respect the original thread, I know about parked cores issue.But as Peter pointed out, parked cores are only there if your HT is on.Now, what bothers me is this: you give system change advices without knowledge what's behind it.As I see it, parking cores is quite good if you are running hyperthreading. It reduces the heat and overall chip strain.If you have no idea what it is and what's it for, then you shouldn't giving advices of above nature.Now, parked cores, even with HT on, can be easily omitted with applying correct affinity mask in fsx.cfg.For instance, if you have HT on, every 2nd core shown in task manager is a HT core, so if you activate only main cores, not HT ones for FSX, FSX isn't even going to "wake" parked cores.And btw. if you aren't doing video editing or similar, you should turn off HT. It's not needed and it doesn't provide anything (except maybe little faster texture loading as someone else on this forum thinks). And it allows for higher overclock (from which FSX benefits directly) with lower temperatures.Oh and btw. you can see in windows if you HT is on or off - don't need to go to the BIOS...

[Selkan 1]

I am not trying to offer advice to anyone; just what has worked for me. Clearly you know more about these matters than I do, and I have not tried to make out otherwise, but your last line is typical. 'you can see in windows if your HT is on or off - don't need to go to the BIOS'. I started my Post saying I would give an easy to follow step by step for those who need just that little extra help. So, in short, don't just quote the line I have put above, but explain how to look in Windows to see if HT is on or off. This might be very basic to you , but until, like everything else in life, you have done it once, you don't know how to look.

[Kosta 122]

Sure sounded like an advice.Quite sorry thought about the last sentance, I was very tired yesterday when I posted that: open task manager to check. If you have 2600K, under performance, 4 windows means 4 cores, HT off, 8 windows, 8 cores active, HT on.If you are seeing 8 cores, you HT is active, and each 2nd window is a HT core of the corresponding main core.

[Selkan 1]

Hi Kost, thanks for this. My FSX setup is on another PC so will check it out later today.

[Selkan 1]

Actually from memory I can confirm that I have twelve cores showing, so my HT must be on. As mentioned before, I was using a little program that set cores to just four (as seen in task manager), but when using the above tweak (main post), I now see twelve. I am getting better performance with HT on and all cores unparked.

[RickY 3]

Actually from memory I can confirm that I have twelve cores showing, so my HT must be on. As mentioned before, I was using a little program that set cores to just four (as seen in task manager), but when using the above tweak (main post), I now see twelve. I am getting better performance with HT on and all cores unparked.

You may be getting better performance because you deleted the affinity mask setting in FSX.CFG??? With HT on, an affinity mask of 14 for example, will cause a significant reduction in performance and introduce stutters. I use an affinity mask of 85 with HT on to try to avoid any interference from virtual cores in FSX by limiting FSX to only the real cores. A rudimentary knowledge of binary values and patterns may be needed here and is explained in detail in other AVSIM forums threads. Just a thought....One thing I noticed in the initial list of steps is that the value of 64 is probably not the % that is suggested. In my registry, this value is in hexadecimal and is equal to decimal 100 (100% then??).Thanks for the detailed and very clear instructions, regardless of their suitability to individual computer system setups.Rick

[Selkan 1]

Hi Rick, thanks for your input. I was not actually using the Affinity Mask setting in my FSX.cfg. I only mentioned it in case it effected others who use it. As to the '64' question, I bow to your superior knowledge. I simply read this elsewhere before writing the Post, but in any event setting Max Value to 0 does appear to unpark any parked cores. BUT, there's always a but; I also read that some people had to sett their Max Value to 100 to obtain the unparked result. I didn't want to mention this in original Post incase it created confusion. I was waiting until someone said it didn't work for them.

[tunnelcat 1]

SelkanVery well written :( - Most of us disable hyperthreading in the BIOS so we may not see all the cores that you are describing. Do you have HT turned on?On my i7 860 HT is turned off so I don't have any parked cores just 4 - cpu0 to cpu3.Most experts recommend turning Hyperthreading off as it can cause thread collisions in FSX and hence the dreaded stuttering plus a huge heat load on the cpu.Does this apply to all quad and six core cpu's ie from the earliest Qxxx quads to the latest SandyBridge 6's?Just a thought.PeterH

Just another question here. I have quite a few other games on the same rig that has FSX on it. Would turning off HT impact the performance of those as well? I too have noticed those irritating stutters while flying in FSX and I would like to try turning off HT to see if that solves the problem, but I don't want to negatively impact my other games in the process.

[Illegitimi non carborundum 4]

TCIt may do if the games are optimised for HT - need to check on the games support forum. The latest BIOS app from Gigabyte means that you can do quite a few BIOS tasks in Windows (still need a reboot) so it would be easy to change from HT on to HT off if that were included.However, as an alternative, there is some software (free/pay) called 'process lasso' (http://bitsum.com/pl...ading_hurts.php) and you use that for HT "avoidance":

"Instead of completely disabling HyperThreading, you can use programs like Process Lasso (free) to set default CPU affinities for critical processes, so that their threads never get allocated to logical cores. We call this feature HyperThreaded Core Avoidance. It is better than completely disabling Hyper-Threading because it leaves the rest of the system free to take advantage of this otherwise useful feature."

So that might be a solution I use this myself for FSX set to 4 physical cores and then set RW3 to all 8 cores (4+4). I haven't experienced any issues.RegardsPeterH

[tunnelcat 1]

Thanks, I'll take a look at 'process lasso'. Pardon my ignorance, but does RW3 mean?Also, should I be using the affinity mask setting in my FSX .cfg file as well? It seems from reading around that this and turning off HT, are 2 of the most important tweaks for getting FSX to run at it's best.