CPU Primary Core Utilization Always 100%?

Any issues, problems or troubleshooting topics related to computer hardware and the Prepar3D client application
jsfs
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Joined: Sat Jan 19, 2019 12:59 am

CPU Primary Core Utilization Always 100%?

Postby jsfs » Sat Jan 19, 2019 1:13 am

Can anyone running 4.4.16.27077 get primary logical core utilization below 100% with any set of settings?

I see it at 100% when P3D is running even with all settings turned down and scenery and add-ons disabled while sitting on the runway with frames limited to 10 (or unlimited), with or without a 253 affinity mask on a 4-core hyper-threading processor running at 4.6Ghz.

Profiling and process explorer show main P3D thread spending 70-80% of time in terrain.dll!terrain_waterlayer_draw function.

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downscc
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Re: CPU Primary Core Utilization Always 100%?

Postby downscc » Sat Jan 19, 2019 5:19 pm

From what I've read here, P3D is designed to fully utilize core 0 (I wouldn't call it the primary core, that's a little misleading in a multi threading environment). This is not a problem. Do not try to "balance" the loading of each core, you'll get nothing for your effort. You may get better results without using affinity mask, I know I do but I've got six cores and there are differences but it's something to play with.
Dan Downs
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jsfs
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Re: CPU Primary Core Utilization Always 100%?

Postby jsfs » Sat Jan 19, 2019 8:17 pm

Could P3D run a constant spin check for synchronization of other cores on core 0 when not fully loading core 0 in the most recent version? I see forum postings showing core 0 not fully loaded with reduced settings.

I'm trying to determine which settings change CPU versus GPU utilization and by how much. I see additional load on core 1 at higher settings, but core 0 never goes below 100%. Maybe better approach is to max everything and then drop back to see utilization difference.

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downscc
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Re: CPU Primary Core Utilization Always 100%?

Postby downscc » Sun Jan 20, 2019 4:40 pm

The AVSIM Guide to Prepar3D has an excellent section on exactly what settings are CPU limited verses those GPU limited. It's by Rob Ainscough who has the creds to prepare such a document. Hope this helps.

As an electrical engineer, "constant spin check for synchronization of other cores on core 0," makes no sense. Processing of threads is enabled by the application but is controlled by the operating system.... and I think asking exactly what you are looking for will get you there faster than by guessing at how CPU loading works.
Dan Downs
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jsfs
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Re: CPU Primary Core Utilization Always 100%?

Postby jsfs » Fri Feb 08, 2019 3:43 am

True, the correct terminology regarding synchronization in my question is thread, not core. The base question is how to determine the extent of CPU impact by varying a CPU-limited setting when the main thread fully utilizes its core regardless of settings, obscuring the impact. The initial question of this topic is if anyone has seen P3D 4.4 utilizing less than 100% of the main thread's core.


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