Does MSFS use AVX? Yes it does! Could someone with crashes test this please?


I was a bit confused, because my CPU boost in the game very seldom to 4,7GHz…
Normally the CPU goes to 4,4GHz in the game and this is coincidentally the offset for my AVX applications!?
So the question is, does this Flight Simulator uses AVX?

Maybe this could be the reason for many game crashes here!? :thinking:



I have checked it and this sim uses AVX!

Could someone with game crashes test this please?
Just set your AVX offset for your CPU in the Bios to -3 and test the game!


Yeah, was wondering days ago why my CPU was melting without being fully loaded, hat to increase my offset, as 5Ghz without AVX offset clearly isnt doable without a nitrogen cooling :smile:

Interesting… The poorly cooled 9900K in my SFF build isn’t being loaded enough to throttle down from its all core 5GHz and I haven’t set a specific offset.

That is true, the CPU usage is not very high…
Otherwise some people say, the have 100% on CPU, that is mysterious

My i9 9900k barely gets past 50% with temps never exceeding 54degC.

Clocked at 5.1 (all cores) with no AVX offset. Machine has been rock solid

AVX offset triggers on multiple things. It could be a pure co-incidence it uses AVX instructions. MSFS could use AVX instructions to a very minimal degree, there is no concrete way to see how “reliant on AVX” it is.

For reference, my CPU is heavily degraded in AVX performance and thermals due to a custom BIOS I have put on it.

  • Prime95 AVX keeps me at around 62-65 degrees
  • Prime95 No AVX keeps me at around 80-82 degrees
  • MSFS when generating autogen (100% usage pinned) keeps me at around 80 degrees.

Sounds like your CPU is on water?
Could you tell me please, what cooler you have?
AVX on Prime95 at 5,1 Ghz… that should be freaking hot!?

I´m not sure what you exactly mean with “generating autogen”?
There differnet AVX instructions! (e.g. Pirime95 AVX512 and AVX2)
One is pretty cool, the other pretty hot, thats why the offset exists!
I would not refer only to the temperature.

Thx for the information so far

Delided with direct to die water cooling - liquid metal as interface

I don’t use Prime but OCCT and AIDA64 - stress testing caused no faults.

Max temp over 4 hours using OCCT that I saw was 81degC with average at 75degC

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Did you do the delidding by your own?
I had thought about that, but for me the risk vs use balance was it not worth…
But nice work :wink:

Back to Topic:
In an other thread here someone confirmed with downclocking he had no crashes anymore!
This down clocking would also effects the AVX settings.

Yes, did it myself using the gear on this site…

There is literally zero way to measure how many AVX instructions are being sent to the CPU.

Chrome triggers an AVX offset, nobody says it is AVX heavy.

I see clock reduction in HWInfo when running FS2020, AVX is -1 stable@4.9ghz would switching AVX instructions off render MSFS2020 unable to start or inefficient? Anyone tested that yet?

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I´m not sure, if you could turn this off… never had thought about that :thinking:

You cannot turn AVX instructions off.

Yup. Tried. Failed. Clocked to stable -1, happy now :smiley:

Theory - MSFS does not use AVX extensively. The AVX offset is triggered by miniscule use of the instruction set.

However it stresses your CPU with other instruction sets very heavily. This leads to instabilities in overclocks being found.

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This is what I thought…
Thank you for confirming this!

I haven’t confirmed it, it is just my theory :slight_smile:

Not far off I think. It has a habit of going from near idle to full load very rapidly which for me at least initially overloaded vrm and needed some changes in load line to adjust.