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do_denver2

CPU spikes every few minutes causing low FPS and stutters

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So, I have everything working pretty well, overall I'm quite pleased with v 2.3 as far as FPS go.  I've got sliders fairly close to max, using ORBX Global/Vector, REX, ASN, add on airports, My Traffic, with no tweaks in P3D.cfg.  I've got HT turned off on my 3770k 4.7ghz.   Typically things are very smooth, and my overall CPU usage is around 50%, core 0 is usually at 100% and the other 3 cores much lower.  Everything is fine in add on GA, just cruising around for fun.

 

However whenever I take my two tubes up, the Aerosoft Airbus or the new Lionheart Learjet, while going at crusie speeds, I notice that randomly every few minutes or so core 0 dips and the other three cores hit 100%, which causes a drop in FPS and heavy stutters, which can last for several seconds.  I've been monitoring things with process explorer, and the spikes come in the P3D process, not some other software running on my machine.  This never happens during takeoff or landing, and I'm assuming it's some issue with texture loading, like it's trying to catch up, although I don't really have blurries or anything noticable happening to the textures so I'm not sure.  I mean everything looks fine.

 

Has anyone else experienced anything like this, or have any suggestions?  Other than this issue I'm having, the sim really runs well.

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Maybe too many hard page faults? Do you know LatencyMon for monitoring?

Spirit

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I'm interested with this also as I observe exactly the same behaviour on my system.

 

It has been worse with 2.3 as now the system hesitates a split second and i see that a window appears but i'm unable to see what's is writen in it as it disapear as soon.

 

I tried disabling things like fsuipc autosave that can do save at regular interval but no change.

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Maybe too many hard page faults? Do you know LatencyMon for monitoring?

Spirit

Hard page faults aren't errors  lol ;-)

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Oh wow, I really hope someone can work out what's causing this behaviour and, more importantly, come up with a solution. I am plagued by exactly the same problem, sailing smoothly along at 50 or 60fps and then for no obvious reason frames plummet to 6 or 7 accompanied by dreadful stuttering. This continues for several seconds before matters return to normal. From my experiments, higher settings appear to increase the frequency of these events but even lowering settings drastically doesn't make them go away completely. I cannot force them to happen and I cannot spot any triggers. Not running any diagnostic software but Task Manager isn't revealing any unusual activity that might point to an explanation. My GPU and CPU temps are also fine. I'm now 100% committed to P3D but this issue is driving me round the bend and really spoiling my enjoyment! Fingers crossed someone gets to the bottom of this.

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Yeah I can't figure it out.  I tried with HT on, I tried turning off various things like water, weather, traffic... But it doesn't matter, every few minutes Cores 1-3 hit 100%, FPS gets erratic and there are stutters.

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Hard page faults aren't errors  lol ;-)

Did I say it's an error? But if there are too much then it may be a bad situation for your system.

Spirit

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What OS? I am running 7 and do not have those issues, but I am not running all of the addons that you are. I do have ORBX PNW.

 

Bob

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Does it do the same with no add-ons? I suggest disabling them all and add them back one by one to find the culprit. This is not an issue in basic P3D. I run with ASN, FTX Global, Vector, openLC, MyTrafficX, Aivlasoft EFT and don't have the issue.

 

Also check that your OS isn't doing some routine task.

 

Vic

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Did I say it's an error? But if there are too much then it may be a bad situation for your system.

Spirit

Lol Spirit apology correct you didn't.

Ps. it's not only the amount but the type of hard page fault ;-)

 

For the interested ones under us:

 

Memory Performance Counters

The following counters all have to do with the management of memory issues. In addition, there will counters that assist in the determination of whether the problem you are having is really a memory issue.

  • Memory : Page Faults/sec. This counter gives a general idea of how many times information being requested is not where the application (and VMM) expects it to be. The information must either be retrieved from another location in memory or from the pagefile. Recall that while a sustained value may indicate trouble here, you should be more concerned with hard page faults that represent actual reads or writes to the disk. Remember that the disk access is much slower than RAM.

  • Memory : Pages Input/sec. Use this counter in comparison with the Page Faults/sec counter to determine the percentage of the page faults that are hard page faults.

    Thus, Pages Input/sec / Page Faults/sec = % Hard Page Faults. Sustained values surpassing 40% are generally indicative of memory shortages of some kind. While you might know at this point that there is memory shortage of some kind on the system, this is not necessarily an indication that the system is in need of an immediate memory upgrade.

  • Memory : Pages Output/sec. As memory becomes more in demand, you can expect to see that the amount of information being removed from memory is increasing. This may even begin to occur prior to the hard page faults becoming a problem. As memory begins to run short, the system will attempt to first start reducing the applications to their minimum working set. This means moving more information out to the pagefiles and disk. Thus, if your system is on the verge of being truly strained for memory you may begin to see this value climb. Often the first pages to be removed from memory are data pages. The code pages experience more repetitive reuse.

  • Memory : Pages/sec. This value is often confused with Page Faults/sec. The Pages/sec counter is a combination of Pages Input/sec and Pages Output/sec counters. Recall that Page Faults/sec is a combination of hard page faults and soft page faults. This counter, however, is a general indicator of how often the system is using the hard drive to store or retrieve memory associated data.

  • Memory : Page Reads/sec. This counter is probably the best indicator of a memory shortage because it indicates how often the system is reading from disk because of hard page faults. The system is always using the pagefile even if there is enough RAM to support all of the applications. Thus, some number of page reads will always be encountered. However, a sustained value over 5 Page Reads/sec is often a strong indicator of a memory shortage. You must be careful about viewing these counters to understand what they are telling you. This counter again indicates the number of reads from the disk that were done to satisfy page faults. The amount of pages read each time the system went to the disk may indeed vary. This will be a function of the application and the proximity of the data on the hard drive. Irrelevant of these facts, a sustained value of over 5 is still a strong indicator of a memory problem. Remember the importance of "sustained." System operations often fluctuate, sometimes widely. So, just because the system has a Page Reads/sec of 24 for a couple of seconds does not mean you have a memory shortage.

  • Memory : Page Writes/sec. Much like the Page Reads/sec, this counter indicates how many times the disk was written to in an effort to clear unused items out of memory. Again, the numbers of pages per read may change. Increasing values in this counter often indicate a building tension in the battle for memory resources.

  • Memory : Available Memory. This counter indicates the amount of memory that is left after nonpaged pool allocations, paged pool allocations, process' working sets, and the file system cache have all taken their piece. In general, NT attempts to keep this value around 4 MB. Should it drop below this for a sustained period, on the order of minutes at a time, there may be a memory shortage. Of course, you must always keep an eye out for those times when you are simply attempting to perform memory intensive tasks or large file transfers.

  • Memory : Nonpageable memory pool bytes. This counter provides an indication of how NT has divided up the physical memory resource. An uncontrolled increase in this value would be indicative of a memory leak in a Kernel level service or driver.

  • Memory : Pageable memory pool bytes. An uncontrolled increase in this counter, with the corresponding decrease in the available memory, would be indicative of a process taking more memory than it should and not giving it back.

  • Memory : Committed Bytes. This counter indicates the total amount of memory that has been committed for the exclusive use of any of the services or processes on Windows NT. Should this value approach the committed limit, you will be facing a memory shortage of unknown cause, but of certain severe consequence.

  • Process : Page Faults/sec. This is an indication of the number of page faults that occurred due to requests from this particular process. Excessive page faults from a particular process are an indication usually of bad coding practices. Either the functions and DLLs are not organized correctly, or the data set that the application is using is being called in a less than efficient manner.

  • Process : Pool Paged Bytes. This is the amount of memory that the process is using in the pageable memory region. This information can be paged out from physical RAM to the pagefile on the hard drive.

  • Process : Pool NonPaged Bytes. This is the amount of memory that the process is using that cannot be moved out to the pagefile and thus will remain in physical RAM. Most processes do not use this, however, some real-time applications may find it necessary to keep some DLLs and functions readily available in order to function at the real-time mode.

  • Process : Working Set. This is the current size of the memory area that the process is utilizing for code, threads, and data. The size of the working set will grow and shrink as the VMM can permit. When memory is becoming scarce the working sets of the applications will be trimmed. When memory is plentiful the working sets are allowed to grow. Larger working sets mean more code and data in memory making the overall performance of the applications increase. However, a large working set that does not shrink appropriately is usually an indication of a memory leak.

Interesting read here also:

https://stackoverflow.com/questions/5684365/what-causes-page-faults

 

 

Cheers

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I cleared out my DLL file so no add ons other than scenery add ons.  Normally, core 0 is at 100 at the other 3 cores much less, and everything is smooth and fine.  However, every few minutes cores 1-3 all go to 100% and there are problems.  I use core temp and the temperatures seem ok, so I don't think it's throttling, but I can lower my clock speeds and voltage and test.

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May or may not be relevant but i was having spikes and drops in fps (but only in certain regions like New Orleans.. turned out vector, specifically the cvx scenery.cfg entry was to blame).

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Thanks I'll try disabling that.  It's not throttling, as I monitored with AIDA64 and CPU temps didn't go above 80 and the graph never indicated any throttling, even during the spikes.

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Well I welcome any suggestions but Vector isn't the cause at my end. Just reinstalled p3d for the umpteenth time on my ssd. Only addon is orbx england and its 04 patch. Started with a night time approach to lba and bam, about 5 seconds into the flight a nasty attack of the stutters that lasted 3 or 4 seconds. Fps before and after was about 60 (settings toned down but still looks gorgeous).

 

Got sysmon on second screen (and no, that's not a clue as I still have stutters when I disable it) but I'm not sure what I should be looking for. Hoping to be able to spot what's happening the next time i get a stutter attack but I would really appreciate guidance on where to focus my attention and how to set up the monitor to assist.

 

thanks

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The one thing that I never understood about page faults is if you have enough physical RAM, then why bother with the paging file at all? I know that Windows likes to cache a lot of OS stuff in the paging file for  potential use later. That's why MS recommends to have a page file even if you have a lot of physical RAM. You can see that mechanism in action if you watch the types of RAM usage with Process Explorer. I have some copies of the OS Service Host (svchost.exe) using 4 GB+ of virtual RAM, which vastly exceeds what that process' maximum peak working set is.

 

When I run Latency Monitor I usually see only 1 or 2 hard page faults and one is always from the Latency Monitor itself. But then again I have 40 GB of physical RAM.

 

Anyone care to share any further insight into page faults?

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When I run Latency Monitor I usually see only 1 or 2 hard page faults and one is always from the Latency Monitor itself. But then again I have 40 GB of physical RAM.

Did you run the FS while you did the LatencyMon? If not you should do and see what happens.

Spirit

 

PS: One can also set the pagefile to zero (means no pagefile) but it's said that this is nonsense. I'm doing this since a few days and it's not so bad.

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I dont pretend to know a lot about the page file except, if I reduce it to 512mb (a suggestion I picked up from somewhere) P3d with high settings oom's in under 1hr, if I set the page file to let windows manage I can fly for 2 or 3 hrs without oom no problem, and I have repeated that test at least half a dozen times.

The fact that I only have 8gb ram may or may not have a bearing on page file use.

 

If the op has altered the page file then it may be worth reseting.

 

Needless to say I have it set to let windows manage.

 

Mick

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Needless to say I have it set to let windows manage.

 

It's always a trade off. Unless you have core 0 excluded with affinity mask there is always the possibility of inducing stutters should Windows decide to do some housecleaning in the middle of a flight.

 

Whatever works for you is what is important.

 

Vic

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The fact that I only have 8gb ram may or may not have a bearing on page file use.

Maybe that's a reason. I've 16 GB and no problems so far without any pagefile.

Spirit

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Dear all,

I’m very happy to have found someone with exactly the same issue.
I’ve a i7-4770k, no OC, 16GB RAM and a GTX 670 2GB. I think a good PC for flight.
Now I’m using P3D v2.3, no edit on Prepar3d.cfg, flying with the new Airbus A319 (the new Aerosoft product delivered on 24th September, I think really optimized for P3D). When I move from the parking stand stutters arise (only few seconds) and then during takeoff. During the flight no issues… and again on landing, where the Airbus isn’t usable at all (too many stutters!) and I cannot land manually (if I have chance I’ve inserted the autoland feature, in the middle of two stutters!).
I’ve monitored the CPU usage with CPU temp software and the results are exactly as yours: core 0 works in a great way, without reaching high loads, despite others (core 1-3)  that produce spikes in those moments (ground movements, takeoff, landing). Absolutely no issues regarding temperature, always at 50-55°C.
I don’t know what I can do… is it an issue regarding P3D v2.3? Do I have too much load inside the simulator? It’s strange, all autogen feature is at medium level…

What do you think about?

 

Thank you,

Alessandro

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