Limited by main thread with an i5-9400F: Is it normal?

User Support Hub Install, Performance & Graphics
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Hello,
Just posting here regarding a question about performance.

I’m currently having a RTX3070 and as a CPU an i5-9400F, everything with 32gb RAM,

Is it normal to have 15-30FPS whatever aircraft and with no custom sceneries ?

It’s most of the time written « Limited by main thread »
In task manager the CPU is most of the time near 100% while GPU is quite low

Thanks a lot !!

Regards

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Yes. Your i5 is simply not powerful enough

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=> Search results for 'Limited by main thread' - Microsoft Flight Simulator Forums

Soooooo many topics…

And yes, depend on your settings, e.g. TLOD, it is currently “normal” :slight_smile:

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@ MAYDAY7415

Look,

I have 60 FPS with I8700 4.5GHz and GTX1070Ti, all with HD res and most HIGH, TAA of course :smiley: so question is what res you have, then try change and compare.

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I know,I’ve read most of them, but nothing fix this issue, I was willing to post something to be sure that I was not crazy enough to forget anything before buying a new CPU for my config :stuck_out_tongue:

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2560x1440, already tried back in 1080 but not much changes

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TLOD was like between 100-200, not even more

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Hope you’ll finally report your settings to see difference :wink: In case same also with settings mostly HIGH with HD then I’m out of curiosity with 30X0 cards as I said already somewhere, compared to my GTX1070Ti 8GB :smiley:

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200 is the Ultra-Setting, and thats noting what your i5 can handle :slight_smile:

MSFS depends stronlgy from CPU power, more exact ( and most important ) from Single-Core-Performance.

An example:
with my setting i8700k/2080TI I can reach ~50fps ( near 4K, ultra , 185TLOD ) , but there is a wide fps range and so I set vsync-target to 50% and fly usually with 38fps ( 75fps monitor ). But there are fps drops till 20 some times. The max fps is limited by my 2080TI, which in most situations is at 100% to reach 38fps , and the fps-drops coming from the CPU ( OC with sync all cores ).

In parallel I build a new PC with a i9-13900k ( not necessary for gaming, just because I do lot of video stuff ) and I flew a while with the same 2080TI. The fps come, as expected not higher because it was limited by GPU, but 99.xxx% of the fps drops are gone and I got stable 38fps. ( I can currently not test what the new GPU give me, because the mainbord slot seems faulty, “whea bsods” with usage of a pci4 gpu-card, and I have to wait for replacement ).

I assume your i5 is ~30% Single-Core / >40% Multi-Core slower than the old i7-8700K, so you know where the limit is. Search in forum for additional settings which are CPU related ( e.g. traffic, etc. ) and try to reduce that.

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Thanks for that clear explanation, I was anyway pretty that the problem was CPU related.

I guess I will have to check the settings in the game.
And if not upgrade to a new CPU :stuck_out_tongue:

Thanks again !!