cleonpack93

CPU Affinity with P3D v4

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I've seen varying opinions on using CPU affinity with v4. Some have said that because of new dynamic controls built in to  P3D itself, manual affinity is no longer needed (I use ProcessLasso to assign CPU affinity rather than changing the .cfg affinity mask). Right now I am running v4 on a 4-processor system (don't laugh. It has actually been working VERY well, way better than FSX was on the same system). Based on the old rules of affinity that I had read, I made it so that P3D is set to use CPU's 1, 2, and 3 and all of my add-ons use CPU 0. So far so good. But, I was wondering if I should just remove the affinity altogether and let it do it's thing.

What has been your experience with v4? What would you recommend?

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I'm in your boat with a 4790k and use Lasso on cores 1-3 with no Hyperthreading.  Works great for me and I'm going to leave mine alone.

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7 hours ago, cleonpack93 said:

But, I was wondering if I should just remove the affinity altogether and let it do it's thing.

Try it an you will see. My experience (4 core and 8 core) tells me P3Dv4 does not need AM/PL.

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I tried AM with 4.1 as i was used to do it in FSX.. BUT there is no really any need.

I fly with everything in one Machine with 2 Monitors:

  • P3Dv4.1
  • Active Sky + ASCA
  • FSrealtime
  • Charts Navigraph (mostly web based)
  • Chrome
  • vPilot (i fly exclusively online)

...and my machine hansles it very well (see it in the sig)...So i wouldn;t bother with Affinity mask.

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7 hours ago, cleonpack93 said:

What has been your experience with v4? What would you recommend?

It works like allways, but you may get blurry textures. On 4 cores CPU with no AM - core 2 and 3 are loading textures, with AM=14 only core 3, and that's not enough on my system. I'm not using it with P3Dv4 becouse of this

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I haven't found any need to mess with the cfg at all, including AM. Smooth like silk with very high settings on my i6700k and gtx1070. I do have dynamic lighting and high res ground textures off, though.

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Prepar3D v4.1
i7 3770K @4.7Ghz (4 cores) running with HT
(980ti - 16GB Ram - Win10 updated - Latest Nvidia Drivers)

From my tests i've found out that setting AM to 252 (first logical and first thread for the apps like ai monitoring, external gauges, Littlenavmap, weather engine, Chaseplane, ecc..., and all other logical and threads on P3D) makes P3D running with slighlty better FPS, but most important a lot of less stuttering.

Logical 0 and thread 0: 10%-25% for the apps

Logical 1: full 100% for rendering. Thread 1: 70%-80%

Logical 2 and 3, Thread 2 and 3: 90%-100% (all other P3D tasks)

Hope this helps.

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Ok W

3 hours ago, bean_sprout said:

AFFINITY_MASK - Just say no!

cheers bs

ok well... damn... before it was FSX... now P3D... it makes me go crazy....

After more testing, HT OFF and no AF, 3-4 fps more and even less stuttering.

DAMN.

This is not a flight simulator. It is a testing-benchmarking tool :D

Considering i ran P3D for one year, 10 months it was running for benchmarking and testing.

...

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I decided to turn affinity off in ProcessLasso and saw an overall reduction in stutters. So there ya go I guess haha

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The only AF mask that works for me (6700K, HT on) is:

[JOBSCHEDULER]
AffinityMask=253

which does nothing else then mask out the first logical core as the main thread runs on Core 0 and I wanted to get rid of everything else on Core 0/1. This makes the sim more fluid for me, but does not give more FPS. All other settings don't really work for me. As this is highly dependent on all other software that is running it is hard to find the AF mask that suites the best for one personally. :-(

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+1 

[JOBSCHEDULER]
AffinityMask=253

CPU: 4770K@4.1, HT on.

The only other tweak I use, and it actually makes a bigger difference, is:

[TERRAIN]
TEXTURE_SIZE_EXP=9

GPU: GTX1070

 

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+1 

[JOBSCHEDULER]
AffinityMask=253

CPU: 4790K@4.6, HT on.

In my case 253 is also the best value at p3d launch.
But it is also interesting after the launch to set AF to 255.
All cores work without saturation.
You can watch this video to know how to do that :

You can also do this automatically.
In my case I launch p3d with a bat file and after 60 seconds I set AF at 255.

Here is the content of my file start_p3d.bat

cmd.exe /c start "Prepar3D" "C:\Program Files\Lockheed Martin\Prepar3D v4\Prepar3D.exe"
timeout 60 > NUL
PowerShell "$Process = Get-Process Prepar3D; $Process.ProcessorAffinity=255"

But to works the .bat must be launch in administrator mode.

 

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Affinity mask has no effect on my P3D4 / 7700K which is the way it should be.

 

Cheers
bs

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