I have P3Dv5.4 and I've been reading up on how to change affinity masks but I find it all very confusing.  I have a Ryzen 5800X that has 8 physical cores with hyperthreading and I have hyperthreading enabled in my pc bios.  I read that it's best to adjust the affinity mask so that hyperthreading cores are disabled so the sim only uses physical cores.  The problem is I'm not sure how to do that.  I did find and mess around with a couple affinity mask calculators I found but I'm not sure if I'm using them right or what exactly the best settings are for my cpu, it's all so confusing.  I haven't been able to find any detailed instructions on how to properly adjust this setting.

I've always had stuttering with P3Dv5 for the longest time (I've read Orbx scenery may make it worse and I have a lot) and I found through lots of testing sim settings that the only thing that fixed it was disabling HDR which is very disappointing because the sim looks so nice with it on.  I read that having P3Dv5 only use physical cores would also get rid of stuttering so I'm thinking if I could learn to do that properly, then I could possibly enable HDR again and even get frame rate improvements.  One thing I should note is since the upgrade from P3Dv5.3 to v5.4 did improve the stuttering to some degree, visually the sim is pretty smooth but the frame rates still stutter, for example, It will go from 60 fps or higher and suddenly drop down to 25 fps for a second, then go back to 60, over and over.

I would greatly appreciate any information and advice anyone could give to help me understand how to adjust affinity masks properly.

Thank you

 

Edit: This is the results of what I came up with using a calculator I just found with just using logical cores, my results are

[JobScheduler]
AffinityMask=21845
P3DCoreAffinityMask=21845

Just wondering if that looks right?  I didn't mess with the schedulers since I don't know how to adjust them.

Edited October 30, 20232 yr by Kalnon

Monitor size, resolution?
Frame rate locked/unlimited/external?
AA settings/NCP mods?

1 hour ago, newtie said:

Monitor size, resolution?
Frame rate locked/unlimited/external?
AA settings/NCP mods?

What does any of that have to do with affinity masks?  I don't understand why you need that information?

If you need to know I have a 16:9, 2560x1440 monitor.  Frame rate set to unlimited, external lock set to 144 fps in my AMD control panel and AA settings I usually use 4x SSAA with FXAA enabled, sometimes I use 8x SSAA but it makes my gpu run hard so I don't always use that much.  I don't understand what you mean by NCP mods?  I don't know that acronym.

I do have a lot of mods installed.  Including, Pilots FSG global mesh (the new 2024 one), high end scenery like lots of Orbx, photoscenery as well as other types of scenery like cityscapes, weather engine and high res textures for sky, clouds, trees, airports, autogen buildings, etc..

Edited October 30, 20232 yr by Kalnon

6 hours ago, Kalnon said:

I have P3Dv5.4 and I've been reading up on how to change affinity masks but I find it all very confusing.  I have a Ryzen 5800X that has 8 physical cores with hyperthreading and I have hyperthreading enabled in my pc bios.  I read that it's best to adjust the affinity mask so that hyperthreading cores are disabled so the sim only uses physical cores.  The problem is I'm not sure how to do that.  I did find and mess around with a couple affinity mask calculators I found but I'm not sure if I'm using them right or what exactly the best settings are for my cpu, it's all so confusing.  I haven't been able to find any detailed instructions on how to properly adjust this setting.

I've always had stuttering with P3Dv5 for the longest time (I've read Orbx scenery may make it worse and I have a lot) and I found through lots of testing sim settings that the only thing that fixed it was disabling HDR which is very disappointing because the sim looks so nice with it on.  I read that having P3Dv5 only use physical cores would also get rid of stuttering so I'm thinking if I could learn to do that properly, then I could possibly enable HDR again and even get frame rate improvements.  One thing I should note is since the upgrade from P3Dv5.3 to v5.4 did improve the stuttering to some degree, visually the sim is pretty smooth but the frame rates still stutter, for example, It will go from 60 fps or higher and suddenly drop down to 25 fps for a second, then go back to 60, over and over.

I would greatly appreciate any information and advice anyone could give to help me understand how to adjust affinity masks properly.

Thank you

 

Edit: This is the results of what I came up with using a calculator I just found with just using logical cores, my results are

[JobScheduler]
AffinityMask=21845
P3DCoreAffinityMask=21845

Just wondering if that looks right?  I didn't mess with the schedulers since I don't know how to adjust them.

To disable hyper threading you need to go into the BIOS where you can do this

An AMD CPU has SMT, not hyperthreading.  HT is an Intel feature.

An AM of 21845 will load P3D onto one virtual processor on each of your 8 physical cores, which I believe is what you were going for.  It won't prevent the OS from running other non-P3D processes on the paired virtual cores, which can get in the way of P3D.  You could try turning SMT off (with no AM set) and see if that makes a difference.

If HDR definitively eliminates your stutters, then that would sure seem to point to an issue with the graphics subsystem, not the CPU...VSync, VRR settings etc.

 

23 minutes ago, Bob Scott said:

An AMD CPU has SMT, not hyperthreading.  HT is an Intel feature.

An AM of 21845 will load P3D onto one virtual processor on each of your 8 physical cores, which I believe is what you were going for.  It won't prevent the OS from running other non-P3D processes on the paired virtual cores, which can get in the way of P3D.  You could try turning SMT off (with no AM set) and see if that makes a difference.

If HDR definitively eliminates your stutters, then that would sure seem to point to an issue with the graphics subsystem, not the CPU...VSync, VRR settings etc.

 

I know SMT and HT work differently but it's similar concept as far as I understand (correct me if I'm wrong).

Good to know I have the AM calculated correctly.  Yeah I would much rather set the P3D affinity mask to only use the physical cores then to turn off SMT in the bios.  It would be a huge pain in the a** to have to keep restarting my pc and going in the bios and changing that setting every time I want to run P3D, then having to repeat the process to enable it again when I need it on.  I will try both ways though and see what happens.

HDR is definitely the culprit, I literally wasted many hours of my life researching, testing and trying sooo many different things and it's the only thing that worked was turning it off.  You may be right, maybe even changing affinity mask settings won't change anything but it's worth a try.  As I said, I would love to be able to have HDR turned on.  It's well known that AMD GPU users (I have a 6900 XT) have to suffer with a lot of issues with certain games (or flight sims), or sometimes the OS itself.

Their drivers are often buggy, due to their all in one driver approach.  I've had more than my share of gpu driver issues over the years.  Each time I update, I'm crossing my fingers, praying, hoping something doesn't go wrong this time...

Edited October 30, 20232 yr by Kalnon

3 hours ago, jkeye said:

To disable hyper threading you need to go into the BIOS where you can do this

Can you not also use an affinity mask that effectively switches off the virtual cores?

8 hours ago, Kalnon said:

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Edited October 30, 20232 yr by newtie
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