CPU Core 0 Usage at 100%

[Nemo 1,305]

I've realized that with P3D running, my CPU Core 0 is always at 100%. Is this normal? I can exclude AV software and Defender as it has been suggested in other threads. It is independent from a/c and scenery where it is located. Even with very low settings CPU Core 0 remains at 100%. No P3D cfg tweaks, No REX, No AS, No Traffic .... always 100%.

Any ideas what could cause this high CPU usage?

[Mace 1,951]

 

37 minutes ago, Nemo said:

I've realized that with P3D running, my CPU Core 0 is always at 100%. Is this normal?

Any ideas what could cause this high CPU usage?

100% is not ideal.

Are you aware of the issue some people are seeing with a recent Win10 update?  It has something to do with cpu usage, I think -- here's an article on it:

https://www.pcgamer.com/a-fix-is-coming-for-a-high-cpu-usage-bug-caused-by-a-recent-windows-10-update/

Do you think this is causing your problem?

[Nemo 1,305]

Yes, I've read about it. I checked my installed Windows updates, but KB4512941 has not been installed on my system. Nothing else running, I just found, that in Task Manager->Details, System Idle Process shows CPU 99! All other processes at 00.

Edit: It seems that "idling process at 99%" is just normal if nothing else is running.

Edited September 16, 2019 by Nemo

[ttbq1 350]

1 hour ago, Nemo said:

Yes, I've read about it. I checked my installed Windows updates, but KB4512941 has not been installed on my system. Nothing else running, I just found, that in Task Manager->Details, System Idle Process shows CPU 99! All other processes at 00.

Edit: It seems that "idling process at 99%" is just normal if nothing else is running.

If you have Icue software you will need to rollback to the previous version, the latest one has issues making core 0 at 100%

[Nemo 1,305]

23 minutes ago, ttbq1 said:

If you have Icue software you will need to rollback to the previous version, the latest one has issues making core 0 at 100%

Thanks. But no ICUE software on my system. The 100% is only when P3D is running.

[Bert Pieke 7,590]

The System Idle process is not P3D...

Look for the prepar3d.exe process.

On my system, it idles at about 13% CPU usage, all of it on the first core..

If you have fps set to unlimited you may see more usage than if you have 30 fps set..

Either way, "close to full" usage on the first core is normal operation for P3D.

Edited September 16, 2019 by Bert Pieke

[Nemo 1,305]

21 minutes ago, Bert Pieke said:

The System Idle process is not P3D...

Look for the prepar3d process.

Thanks Bert, I know. But in TaskManager, I don't see any other process using CPU more than 2% during P3D is running. P3D is about 20% in TM.

I'm only saying that Core0 is always(!) at 100%. I'm pretty sure that this was not alike on my system some time ago. Core0 was used to be in the higher 80s or 90s but not continuously at full 100%. I'm monitoring with MSI Afterburner and RTSS.

Edited September 16, 2019 by Nemo

[Bob Scott 7,745]

4 hours ago, Nemo said:

I've realized that with P3D running, my CPU Core 0 is always at 100%. Is this normal? I can exclude AV software and Defender as it has been suggested in other threads. It is independent from a/c and scenery where it is located. Even with very low settings CPU Core 0 remains at 100%. No P3D cfg tweaks, No REX, No AS, No Traffic .... always 100%.

Any ideas what could cause this high CPU usage?

If you have unlimited frame rate set and no other frame throttling mechanism in place like VSync to a 30Hz monitor, or RTSS scanline sync, then 100% is normal as the CPU is trying to crank out as many frames as it can.

Even without setting unlimited frame rates, the sim may try to build pre-rendered buffer frames and remain heavily saturated...that's something you might be able to address in nVidia Control Panel or NVI.

Regards

[Nemo 1,305]

6 minutes ago, w6kd said:

If you have unlimited frame rate set and no other frame throttling mechanism in place like VSync to a 30Hz monitor, or RTSS scanline sync, then 100% is normal as the CPU is trying to crank out as many frames as it can.

Even without setting unlimited frame rates, the sim may try to build pre-rendered buffer frames and remain heavily saturated...that's something you might be able to address in nVidia Control Panel or NVI.

Regards

NVCP/NVI, that seems to be a good hint. I'll check this later. I was a bit confused about those win10 update problems.

Edited September 16, 2019 by Nemo

[Pete Dowson 558]

1 hour ago, Nemo said:

I'm monitoring with MSI Afterburner and RTSS.

Aha! I think it is RTSS which pushes core 0 to 100% It doesn't appear to do any harm. It just seems to be soaking up idle time but not demanding it.

I've actually found that limiting frame rates using the RTSS limiter (I don't use the scanline facility, just a straight 30 fps limit) allows P3D4 to run much smoother than any of VSync, P3D's FR Limiter or nVI's one, and this is despite RTSS soaking up that idle time!

Pete

 

[Nemo 1,305]

8 hours ago, Pete Dowson said:

Aha! I think it is RTSS which pushes core 0 to 100% It doesn't appear to do any harm. It just seems to be soaking up idle time but not demanding it.

I've actually found that limiting frame rates using the RTSS limiter (I don't use the scanline facility, just a straight 30 fps limit) allows P3D4 to run much smoother than any of VSync, P3D's FR Limiter or nVI's one, and this is despite RTSS soaking up that idle time!

Pete

 

Interesting. But this would be in contradiction with my former observations when I've also used MSIAB/RTSS for monitoring. And if I watch Robs recent video (Honolulu thread) it shows that his CPU0 core is not always at 100% and it looks like it is monitored by MSIAB/RTSS too.

It must be something else. NVI/NVCP is on P3D default. P3D setting low, P3D default situation, frames locked at 20. No MSIAB/RTSS. I monitored with TaskManagers Resource Monitor and Core=0 is still at 100% all the time. As soon as I shut down P3D, Core0 usage goes down to low percentages..

Edited September 17, 2019 by Nemo

[Tomaz Drnovsek 440]

Just toggle CPU 0 off/on in Set Affinity in Task Manager and it won't be running at 100% anymore.

[Nemo 1,305]

27 minutes ago, Tomaz Drnovsek said:

Just toggle CPU 0 off/on in Set Affinity in Task Manager and it won't be running at 100% anymore.

Great, that did the trick. Thank you so much Tomaz!

I believe to remember that I've read about this OFF/ON trick somewhere else some time ago. Getting old ...  I'd still like to know what causes this 100% CPU Core=0 usage. I've never been affected with this problem until recently. I'm also not sure if it has any big performance/smoothness impact, but it simply did not look right to me.

Edited September 17, 2019 by Nemo

[Tomaz Drnovsek 440]

1 minute ago, Nemo said:

Great, that did the trick. Thank you so much Tomaz!

I believe to remember that I've read about this OFF/ON trick somewhere else some time ago. Getting old ...  I'd still like to know what causes this 100% CPU Core=0 usage. I've never been affected with this problem until recently. I'm also not sure if it has any big performance/smoothness impact, but it simply did not look right to me.

If somebody is experiencing 100% on CPU 0 all the time when in P3D, this usually solves it. I'm also not sure if it actually does anything but I agree it doesn't look right :) I usually do the toggle thing (yes, you have to do it every time) just because why not but sometimes I also forget to do it and I can't really say it makes any difference in performance. The only practical reason I see for doing that is that when P3D actually pushes CPU 0 to 100% because of an actual load and you start getting performance issues and stutters you know one of your CPU's is maxed out for real.

[Seat* 53]

I observe the same thing, Core0 100% when P3D is running. Now I wonder what is really the difference between turning off Core 0 in Windows or Process Lasso (advantage that you don't have to do it every time) compared to doing it in P3D.cfg. In this forum it has always been said that it is in cfg that affinity should be put.

 

/Thomas