ntdll.dll Crash - Really related to overclocking?

[tszchun_anson 3]

Dear all,

Today I just finished clean installing my PC and got P3D v4.2 installed. While having my first returning flight, the sim crashed with ntdll.dll as the fault module, which I have never expected and experienced before.

Then I read the CTD guide here and wondered if overclocking was the culprit. I have a 6700k overclocked to 4.6GHz with around 1.25v, and two 4GB ram sticks overclocked to 3000MHz with the factory-loaded XMP profile. Actually my system has been running perfectly in Windows without any BSOD, except rare memory-related boot failure which can be easily "tackle" by resetting (restarting) the PC solely. It has also passed a variety of stress tests so I thought stability should not an issue.

Since my sim was just clean installed with just few add-ons, like ASP4, GSX that kind of mainstream programs, hence I don't think the culprit was on software side. That's why I am very confused right now. Personally I prefer not to reset my overclock setting, because now even with CPU overclocked my sim still had very low fps (~15) when cruising above the dense cloud layers...

So my concern is how likely overclocking being the cause of ntdll.dll crash. Base on your observation, does overclocking cause ntdll.dll very often?

Anson

[Jim Young 2,356]

Ever since FSX, it is a well-known fact throughout the flight simulation community that too high or too low cpu voltage would cause an ntdll.dll.  It could also be cause poor overclocking of the memory modules.  There use to be a memo showing that if the error report showed 024 in the error report, it meant the cpu voltage was too high or too low.  I had it on my system.  Cannot find it now.  FSX/P3D trigger these voltage anomalies because I have overclocked a system and it was extremely stable when running the Intel Burn Test, Prime95, and AIDA64.  My system was stable and would not crash using those programs.  Then I ran FSX or P3D and I would get an ntdll.dll error.  If I lowered my overclock a couple of GHz or went back to the Optimal Defaults, I got no crashes.  The ntdll.dll crash is quite common but there are other things that cause an ntdll.dll crash and it is not just a bad overclock.  For instance, many used the MyTrafficX program for AI.  It is well-known that if you have the mytrafficmil.bgl enabled in P3DV4, it will cause a crash when you get near AI military aircraft or near a military airbase.  There are other reasons for the crash as explained in the AVSIM CTD Guide like corrupted or outdated hardware drivers (and one major reason I recommend one get a driver update program and make sure all of their hardware like SATA controllers and USB ports are kept up-to-date as bugs are found constantly.

I had my current system overclocked to 5.0GHz and was getting occasional ntdll.dll errors.  Lowered the overclock to 4.7GHz and got them again.  One thing I was trying to do was overclock my memory to 3500MHz and my ASUS Z270 board would not allow it.  So I used factory-loaded XMP profile which overclocks the memory to the max and my sim ran okay for a day or two but got crashes again so went back to the optimal default (4.5GHz).  I heard I can have the optimal defaults and the XMP Profile running at the same time.  I already had it in optimal default so just loaded the XMP profile and save the configuration.  It sits at being overclocked to 4.5GHz which, in my humble opinion, is more than enough overclock for P3DV4. The problem you might have is the fact you want to also overclock your cpu to something and that may not work. Of course, you can try.

The cpu voltage for a 6700K should be around 1.35 so your voltage may be too low.

[Sartanius 399]

It certainly was the main culprit for me in the past when over clocking my former 5930K.  P3Dv4 (and FSX) are the best stress test for overclocking.  RealBench, Prime95, and the others are good at rooting out fragile OCs, but even when I had a long and successful stress test with zero problems, I'd still get the ntdll.dll crash with Prepar3D.  Once I throttled down the OC settings, the ntdll.dll crashes went away, and all was well.

[vgbaron 3,496]

Still the best stress test for OC AS IT RELATES to FSX/P3D is OCCT.   Only OCCT stresses the memory AND cpu in essentially the same way they are used in FSX/P3D. The other tests basically test the number crunching and the heat that generates. I have seen many systems pass P95 etc and flat fail OCCT. If you can run OCCT for an hour your system should handle anything FSX/P3D can throw it it.

Vic

[lodestar 186]

This is a very interesting subject for me. I did a lot of investigation about this. And yes, it can be related to overclocking, becouse one of the causes is the hardware - like Jim said, it can be a low Vcore. This is why it's recommended to add a bit more Vcore to your stable overclock.

The usual causes for Ntdll.dll errors are corrupt or damaged version of the ntdll.dll file itself(rarely), corrupt hardware drivers(important, usually GPU Drivers), problems between Windows and other programs / applications, hardware problems(rare, but this includes overclocking), DEP(Data Execution Prevention), or a bad RAM module. 

So, you should update everything, uninstall GPU driver completely(like this https://www.wikihow.com/Uninstall-Nvidia-Drivers), then install the latest GPU driver, disable DEP for P3D(i have DEP disabled completely on my PC, but this is up to you)and test your RAM. For overclocking, i do recommend realbench for testing. Intel burn test will show you the highest possible CPU load, but it's unlikely you are ever going to experience it, i'm not using it. Just try to get your CPU stable with realbench, then add a bit of Vcore. I added some Vcore to my stable overclock after testing, for extra stability, and i didn't touched it for 5 years now. I have a 2700K at 4.8Ghz, and my temps with P3DV4 are in mid 50, 54-55c with Vcore of 1.4,  which is great. And i don't get this error, btw.

I hope you will find some of this informations useful. if you have any questions please feel free to ask

[tszchun_anson 3]

7 hours ago, Jim Young said:

Ever since FSX, it is a well-known fact throughout the flight simulation community that too high or too low cpu voltage would cause an ntdll.dll.  It could also be cause poor overclocking of the memory modules.  There use to be a memo showing that if the error report showed 024 in the error report, it meant the cpu voltage was too high or too low.  I had it on my system.  Cannot find it now.  FSX/P3D trigger these voltage anomalies because I have overclocked a system and it was extremely stable when running the Intel Burn Test, Prime95, and AIDA64.  My system was stable and would not crash using those programs.  Then I ran FSX or P3D and I would get an ntdll.dll error.  If I lowered my overclock a couple of GHz or went back to the Optimal Defaults, I got no crashes.  The ntdll.dll crash is quite common but there are other things that cause an ntdll.dll crash and it is not just a bad overclock.  For instance, many used the MyTrafficX program for AI.  It is well-known that if you have the mytrafficmil.bgl enabled in P3DV4, it will cause a crash when you get near AI military aircraft or near a military airbase.  There are other reasons for the crash as explained in the AVSIM CTD Guide like corrupted or outdated hardware drivers (and one major reason I recommend one get a driver update program and make sure all of their hardware like SATA controllers and USB ports are kept up-to-date as bugs are found constantly.

I had my current system overclocked to 5.0GHz and was getting occasional ntdll.dll errors.  Lowered the overclock to 4.7GHz and got them again.  One thing I was trying to do was overclock my memory to 3500MHz and my ASUS Z270 board would not allow it.  So I used factory-loaded XMP profile which overclocks the memory to the max and my sim ran okay for a day or two but got crashes again so went back to the optimal default (4.5GHz).  I heard I can have the optimal defaults and the XMP Profile running at the same time.  I already had it in optimal default so just loaded the XMP profile and save the configuration.  It sits at being overclocked to 4.5GHz which, in my humble opinion, is more than enough overclock for P3DV4. The problem you might have is the fact you want to also overclock your cpu to something and that may not work. Of course, you can try.

The cpu voltage for a 6700K should be around 1.35 so your voltage may be too low.

Thanks so much for so reply.

May I know if your finding is a 100% replicable? Comfirm you got no ntdll.dll crashes every time the CPU is at default clock? This is the largest concern of mine because resetting my overclock is a big sacrifice from my perspective haha. If I let my 6700k stay at default clock, it will only be 4.2GHz which is a large difference from current clock 4.6GHz. 

And sorry for my typo. I have 1.296v vcore in manual voltage mode set in UEFI and 1.325v shown in CPU-Z. Cache frequency is also set to 4.1GHz. I am considering to add a bit VCCIO and System Agent voltage to increase the stability of memory because every post failure I have ever encountered is memory-related.

Anson

[tszchun_anson 3]

7 hours ago, dmiannay said:

It certainly was the main culprit for me in the past when over clocking my former 5930K.  P3Dv4 (and FSX) are the best stress test for overclocking.  RealBench, Prime95, and the others are good at rooting out fragile OCs, but even when I had a long and successful stress test with zero problems, I'd still get the ntdll.dll crash with Prepar3D.  Once I throttled down the OC settings, the ntdll.dll crashes went away, and all was well.

Thanks for your sharing.

Did you find throttling down affecting performance significantly?

Anson

[tszchun_anson 3]

5 hours ago, lodestar said:

This is a very interesting subject for me. I did a lot of investigation about this. And yes, it can be related to overclocking, becouse one of the causes is the hardware - like Jim said, it can be a low Vcore. This is why it's recommended to add a bit more Vcore to your stable overclock.

The usual causes for Ntdll.dll errors are corrupt or damaged version of the ntdll.dll file itself(rarely), corrupt hardware drivers(important, usually GPU Drivers), problems between Windows and other programs / applications, hardware problems(rare, but this includes overclocking), DEP(Data Execution Prevention), or a bad RAM module. 

So, you should update everything, uninstall GPU driver completely(like this https://www.wikihow.com/Uninstall-Nvidia-Drivers), then install the latest GPU driver, disable DEP for P3D(i have DEP disabled completely on my PC, but this is up to you)and test your RAM. For overclocking, i do recommend realbench for testing. Intel burn test will show you the highest possible CPU load, but it's unlikely you are ever going to experience it, i'm not using it. Just try to get your CPU stable with realbench, then add a bit of Vcore. I added some Vcore to my stable overclock after testing, for extra stability, and i didn't touched it for 5 years now. I have a 2700K at 4.8Ghz, and my temps with P3DV4 are in mid 50, 54-55c with Vcore of 1.4,  which is great. And i don't get this error, btw.

I hope you will find some of this informations useful. if you have any questions please feel free to ask

I am also wondering if my Vcore is too low, which causes the ntdll.dll crash. I will try to increase Vcore a bit and see if the crash still exists. However, I don't think it relates to GPU driver because my system was just fresh installed and "clean installation" was checked in the installation wizard. 

I will disable DEP tonight and see if it works. Is there any impact of disabling it except lack of protection?

[Jetset408 108]

I recently had the same CTD to desktop issue with P3d 4.2. My PC has always been stable with my 6700k overclocked to 4.6GHZ at the same voltage you mention, and with XMP profiled memory. P95 stress tested initially, then everything left in place for about 12 months.

Then I started getting CTDs since around Christmas. Some were ntdll faults, others left no log entry.

Penny dropped that I had a few months ago upgraded to a 1080Ti from a 1070 and also started using the more taxing p3d 4.2 (with dynamic lights). This I believe added some instability under load - perhaps through power load. It became so i could replicate the CTD by creating overcast weather in AS4, flying the FSL320 through it at night with dynamic lights turned on, in the region of EGLL. 

Since turning off my overclock and XMP I have had no more CTDs. 

And more interestingly.... I didn't notice a performance hit!

[tszchun_anson 3]

26 minutes ago, Jetset408 said:

I recently had the same CTD to desktop issue with P3d 4.2. My PC has always been stable with my 6700k overclocked to 4.6GHZ at the same voltage you mention, and with XMP profiled memory. P95 stress tested initially, then everything left in place for about 12 months.

Then I started getting CTDs since around Christmas. Some were ntdll faults, others left no log entry.

Penny dropped that I had a few months ago upgraded to a 1080Ti from a 1070 and also started using the more taxing p3d 4.2 (with dynamic lights). This I believe added some instability under load - perhaps through power load. It became so i could replicate the CTD by creating overcast weather in AS4, flying the FSL320 through it at night with dynamic lights turned on, in the region of EGLL. 

Since turning off my overclock and XMP I have had no more CTDs. 

And more interestingly.... I didn't notice a performance hit!

We have the exact same situation! I have also upgraded to 1080Ti from 770 (before clean installing Windows).

I remember that just before my ntdll.dll crash, there are so many clouds and their layers underneath my cruising PMDG 777, causing the FPS to drop significantly to around 15-20fps. I am not sure whether it implies something...

Are you sure turning off overclock and XMP are the only thing you have done in order to solve the crash? Will it be a placebo?

Anson

[Jim Young 2,356]

10 hours ago, tszchun_anson said:

Comfirm you got no ntdll.dll crashes every time the CPU is at default clock?

So far I have not received an ntdll.dll crash saving the optimal default setting in the BIOS (4.5GHz; 4.2GHz for you) and then going back in and enabling the XMP profile and saving again (so I can have the ultimate speed for my memory modules).  In P3DV4.2, does overclocking your system to 4.6-5.1GHz really provide better FPS/performance that is such an increase it is worth the risk of manually overclocking and having periodic crashes?  Using the FSUIPC utility, you can enable the FSUIPC log under logging and record the FPS for a flight.  For instance, I flew the CS757 from FSDT Chicago to FlightBeam Wash Dulles using AS16 for weather and GEP3D for textures and got the following:

Minimum frame rate was 12.6 fps, Maximum was 57.7 fps
Average frame rate for running time of 4451 secs = 33.9 fps
Maximum AI traffic for session was 301 aircraft
Memory managed: 2923 Allocs, 2922 Freed

Getting an average of 34 fps during the flight is more than excellent.  If the fps fell to 12.6 during the flight I certainly did not feel it and it most likely happened while at KORD preparing for takeoff.

Personally I would make a copy of all of your overclocked settings in the your BIOS by using the PrintScreen then saving to a flash drive.  You can also see if your Board has the option to save the OC Profile to a flash drive.  You can then set up the optimal defaults/XMP profile as I suggested above and see if there really is any difference.

[lodestar 186]

9 hours ago, tszchun_anson said:

I am also wondering if my Vcore is too low, which causes the ntdll.dll crash. I will try to increase Vcore a bit and see if the crash still exists. However, I don't think it relates to GPU driver because my system was just fresh installed and "clean installation" was checked in the installation wizard. 

I will disable DEP tonight and see if it works. Is there any impact of disabling it except lack of protection?

First, ensure to get stable overclock - enough Vcore and good temps. Higher clock is the best thing you can do for FS, but it will cause problems if unstable. Feel free to ask anything about in our hardware forum, we have a lot of knowledgeable members who can help you with this.

About disabling DEP, there's no any other impact. Maybe a bit more responsive PC. But i do have some extreme settings here - i'm always disabling almost all of OS protection and anything else that uses CPU cycles - not recommended unless you know what you are doing. This is why i recommended to disable DEP for P3D only.

[Jetset408 108]

On 14/04/2018 at 8:27 AM, tszchun_anson said:

We have the exact same situation! I have also 

Are you sure turning off overclock and XMP are the only thing you have done in order to solve the crash? Will it be a placebo?

Confirmed. It's all I have done. It's a fresh installed PC and nothing else has been changed. Plan was to work up a new overclock, but given I didn't notice a particular drop in performance, I've decided not to bother and to instead spend my limited available time on using the Sim.

[Sartanius 399]

On 4/13/2018 at 10:50 PM, tszchun_anson said:

Did you find throttling down affecting performance significantly?

Anson,

Sorry to get back to you so late with my response.  I throttled down incrementally until P3Dv4 was stable on a semi-long flight (3-4 hours).  Moving down from 4.5GHz to my final of 4.3GHz really only affected FPS about 10% or so.  Clearly the higher cycles the better, but 200Hz didn't hurt too bad.  Remember, the stock GHz for the 5930 is 3.5GHz, so my final OC to 4.3GHz gave me quite an FPS boost.