CPU Temperatures fluctuating

[CaptainLHKLM]

Hi all,

I was hoping some of you could provide me with some advice. I've been using the latest version of P3D V5 on my PC with the following specs:

CPU - i7 10700KF (non OC, just default BIOS settings. Normally runs ~4.6-4.7 GHz when using P3D)
GPU - RTX3080
RAM - 32 GB Ram
Storage - 3 x SSD, with P3D on an NVMe disk.
Cooling - H100i water cooling with 4 fans (3 on the front, one on the back), with everything set to "Balanced" or "Extreme" settings in iCUE.

My temperatures are 55-65 degrees C on average, but every few (maybe 10?) seconds I get a peak of a few cores to 75-80 (measured using CoreTemp). To measure average temperature, I use Speccy, which I haven't seen above 70 degrees, and is normally between 55-60, sometimes 65 degrees. While the peaks on those cores are still under TjMax by 20 degrees, I am trying to find why the temperatures fluctuate so much, or is this normal behaviour?

The reason I ask is that it still seems somewhat uncomfortable to run P3D when away from home for hours. For comparison, MSFS, and every other game, runs very cool (around 55 degrees constantly) using the same water cooling settings. It feels as if the rest of my PC runs a little slower when I'm using P3D, but that might just be placebo, and probably doesn't help to diagnose the problem :). I have attached links that show screenshots of task manager, core temp showing the temperatures of individual cores, Speccy showing a log of the average temperature, and my P3D settings in case it helps.

Some extra information is that I've already reset my BIOS settings (almost everything is on "Auto"), I've tried all iCUE cooling settings, I have reset my P3D CFG a couple times (which doesn't take away the fluctuations, but shifts all the temperatures down by 5-10 degrees, given the settings are lower than what I am running now). The P3D tweaks I am using is GlobalTerrainView = True, and I have affinity mask to use each core apart from 0 and 1 (AffinityMask=65535, P3DCoreAffinityMask=65532). I am using Refresh Rate as Adaptive/2 (30 Hz) and FPS lock to 32 in nVidia Control Panel.

For the hardware, I have cleaned the PC fans, and have checked by feeling the airflow with my hands. I have also checked the orientation of the fans to make sure the airflow is correct.

Any help is appreciated!

Daniel

Links:
https://ibb.co/P5m6Hgs
https://ibb.co/HBtMyP8
https://ibb.co/6PPD0N2
https://ibb.co/BcM7mM1
https://ibb.co/ws5TnyY
https://ibb.co/mJrjg9q

[Martyson]

Hello CaptainLHKLM ,
Daniel

Are you testing P3D with the default flight, no AI Traffic, no weather program, or any other Flight Sim Add-ons running?

[CaptainLHKLM]

Hi Martyson,

This is indeed how I was testing! Just the default aircraft and airport when you load the sim. I sometimes used addon aircraft to gauge the difference too. I can get the same task manager screenshot and core temp information with the default aircraft and airport once I land (currently in a long haul :) ). Is there any other information you would like?

Kind regards,

Daniel

[Martyson]

Hi Martyson,

This is indeed how I was testing! Just the default aircraft and airport when you load the sim. I sometimes used addon aircraft to gauge the difference too. I can get the same task manager screenshot and core temp information with the default aircraft and airport once I land (currently in a long haul :) ). Is there any other information you would like?

Kind regards,

Daniel

No large CPU temp fluctuations on my setup:
P3D academic 5.3.17.28160

How to Post Screenshots (by Chris Metel):
https://www.prepar3d.com/forum/viewtopi ... 98#p238598

[CaptainLHKLM]

Hi Martyson,

I have the test results here. We seem to have pretty similar temperatures on the ground, but once I take off I get these peaks toward 70 degrees C on core temp, but the average across all cores is lower. This is with every addon selected off in the P3D menu. Also, thanks for sharing the screenshot help!

[CaptainLHKLM]

I've tested with some more settings, with a stable OC, etc. but really can't find anything to change the erratic CPU use (which I'm guessing is causing the CPU cores to speed up and down and up and down, etc., causing them to generate heat quickly and cool down after). Does anyone have any more suggestions?

[Martyson]

Hello CaptainLHKLM
“CPU - i7 10700KF (non OC”
“I've tested with some more settings, with a stable OC”

My setup is not Overclocked.

[CaptainLHKLM]

Hi Martyson,

Sorry for that. What I meant to say was that I've tried 1) using the default BIOS (CPU) settings, and 2) settings an OC manually. In other words, my CPU "turbos" to about 4.7 GHz when left on its own using default BIOS settings. However, I have also tried an OC (or actually, an underclock) at 4.6 GHz, to see if the turbo is what causes the spikes. Setting the CPU to run slower than usual did nothing however, and I retain the spikes only within P3D.

[KevinKaessmann]

Just a hint:
it seems, FSX up to P3D 4.5 renders the environment in "chunks" - not continously.
That would explain the spikes every 10 seconds.
If P3D 5 does the same and maybe uses AVX/AVX2 instructions (processor gets hotter as for normal fpu instructions)
in combination with a too high manufacturer preset mainboard wattage, that could lead to these thermal spikes.
Newer processors aren't allowed to run continuously all cores on turbo frequency,
in detail you will find here some information:
why-intel-processors-draw-more-power-than-expected-tdp-turbo
Intel 10th Gen CPU Power Consumption Explained: PL1, PL2, and Tau

[Manuk]

You can fix CPU temperature jumping up and down by cleaning the dust from CPU, reapplying thermal paste, cable management, upgrading CPU cooler, resetting cooler, replacing older cooler, checking for malware infection, air circulation, adjusting CPU setting, speeding up existing fan.

[CaptainLHKLM]

I recently installed P3D to give the FSLabs A320 some more love, and after experimenting with the settings I found that the "Texture Resolution" setting under "World" (not the texture resolution under "Display") is the culprit. If I set it to 1 m, I get temps around 50 degrees, sometimes 60s and the rare spike in the low 70s. If I turn it to 30 cm, my temps shoot up to 70 degrees straight away and stay there. I've tested this separately from the other terrain, scenery objects, cloud draw distance, lighting and shadow settings (I can push those up until I get 20 fps but my temperatures are still fine), so I'm confident that the problem is the texture resolution. Does anyone know why this could be, or how to work around it? Whether I have dynamic texture streaming on or off doesn't make a difference, and neither does "use high-resolution terrain textures". Perhaps some of you could test to see if turning texture resolution all the way down and then all the way up makes a difference, as it seems like some other P3D users have the same as I do (https://www.youtube.com/watch?v=8er_s9ehPRY&t=30s as you can see in the CPU temps here).

Best wishes!

[Martyson]

Hello CaptainLHKLM ,

Which P3D product / version number?

I tested with the P3D default flight.

I tested with P3D Academic 5.4.9.28482

1m and 30cm and the results for both :

FPS 58 to 64

CPU temp 42

[CaptainLHKLM]

Hello CaptainLHKLM ,

Which P3D product / version number?

I tested with the P3D default flight.

I tested with P3D Academic 5.4.9.28482

1m and 30cm and the results for both :

FPS 58 to 64

CPU temp 42

Hi Martyson,

Thanks for replying! I'm using P3D V5 Professional 5.4.9.28482.

I'm not running any overclocks either, just to put it out there. I also lock FPS to 32 in the nvidia control panel, so if anything I'd expect my PC to be utilised as much or less than when setting fps to unlimited in P3D. Out of interest, what tool are you using to measure temperatures, Martyson?

Best wishes,

Daniel

[CaptainLHKLM]

It seems at least one other user has identified that texture resolution plays a huge part: https://www.avsim.com/forums/topic/6367 ... nt=5005156

[Martyson]

Hello CaptainLHKLM ,

Which P3D product / version number?

I tested with the P3D default flight.

I tested with P3D Academic 5.4.9.28482

1m and 30cm and the results for both :

FPS 58 to 64

CPU temp 42

Hi Martyson,

Thanks for replying! I'm using P3D V5 Professional 5.4.9.28482.

I'm not running any overclocks either, just to put it out there. I also lock FPS to 32 in the nvidia control panel, so if anything I'd expect my PC to be utilised as much or less than when setting fps to unlimited in P3D. Out of interest, what tool are you using to measure temperatures, Martyson?

Best wishes,

Daniel

Hi CaptainLHKLM ,

I currently use Unlocked Target frame rate and Vsync On in P3D Options.
I use P3D default AffinityMask.
I never use the nvidia control panel.
I use Speccy for Diags.

I see no problems on my primary PC with P3D4, P3D5, P3D6 Personal, Xplane11 or MSFS(2020).

On my second PC no problems with Xplane12, MSFS(2020) or FSX Steam.