Intel to AMD change performance terrible

Hello all. I just switched from an intel cpu to AMD, MY specs: 7800x3d, x670 mb, RTX 4090, 32 gb ddr5, win 11, 2tb nvme drive. CPU benchmarks well, no memory errors, 4090 also has good numbers, and the nvme is a fast WD black sn850x.
I have just finished reinstalling MSFS for the 4th time, have installed to default location - random location on C: and even to a totally different drive. This is what happens the 2.1gb installer loads game starts the installs the 168gb, at the end it senses decent hardware and recommends all ultra settings and sets them. Before I install the 68gb of extra updates I set a destination airport with default aircraft (zero in community folder) start the flight and are seeing 95 fps - Great. Install the other updates and results are same. Quit to desktop return later start sim which takes forever to load noticeable stutters even in loading images - start flight less than 10 fps it looks like slow motion slide show. Exact same results all 4 installs. Everything on computer works fine even Steam game’s. The hardware seems fine this is my first shot at AMD am I missing something? Any thoughts would welcome thanks.

Start with reseting all Nvidia control panel settings to defaults (if you have messed with them) then apply a default config like Ultra in MSFS and start tweaking from there if needed.

To be fair a clean OS reinstall could be beneficial. It’s like you got a new system, different chipset drivers, etc… Reinstalling the sim is not enough

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I wholeheartedly reiterate this ^.

There’s a thread here where someone with a new AMD 7XXX had significant performance issues and it was determined the Windows install their PC builder had used was a flash that didn’t account for his CPU. Upon reinstalling Windows fresh the issues went away.

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Thanks for the info so far that was going to one my last ditch options. I am still curious why the performance was so good immediately after install but so poor on next start of MSFS

I’ve just switched to ryzen 7 7800x3d with an existing windows install without any problems.
What are your temps like ? I expect you’ve got a decent cooler.
Update bios: my new B650 came with an old bios.
Is your memory running at full clock speed ? Did you activate it in bios ?
Good luck.

If you took your drive out of your Intel system and used it for your AMD system unchanged this would definitely cause your PC to not run optimally.

Well, I know that and that’s what I aimed to highlight in a polite way :slight_smile:
@insom50 let us know if you’re good or still having an issue

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May I ask why? I’m no expert, for sure, but AFAIK both systems run the same OS exactly the same. Certainly the chipset drivers are different, and the BIOS are different, but the BIOS is lower level code.

OP, you did update your chipset drivers, right? And you have the most current system BIOS, right?

The main reason why is the Hardware Access Layer kernel drivers in Windows, Windows actually uses a slightly different kernal driver for Intel vs AMD, although they are both compatible with each vendors CPU’s there are optimisations per vendor in the HAL. For example SMT optimisations vs HT optimisations. In addition the north and south bridges on the chipset for Intel work subtle different to AMD. Especially now a lot of the northbridge functionality is now built into the CPU.

Just to also add, Windows cant swap in a new HAL, it just uses the existing one thats installed. Typically in older windows versions this would cause a blue screen swapping a drive over from AMD to Intel or visa versa. With Windows 10 its a bit more forgiving but you still get the above issues.

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Thank you for that. Very educational. Some stuff I absolutely did not know.

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Sorry - I meant to reply to the OP and reinforce what you had said however my rush to do so on a small phone screen got in my way! :face_with_peeking_eye:

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Hi everyone
I am still here and thank all for your suggestions. I just started a clean win 11 install so I get to install MSFS for the 5th time plus every thing else. I will let you know the results.
Thanks again

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Your suggestions solved my problem! I did a clean Win 11 install, updated the chipset drivers and bios then reinstalled MSFS. I now have a stable sim with good numbers on the monitor - have not tried VR yet.
Thanks again for all your help

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I’m so glad the community was able to help :slight_smile: now go fly … fly like a bird muhahahahaha :slight_smile:

This is what I love to read!

Happy to hear the good news! All the best in the future and the community is always here :slight_smile: