My new RTX 3080 is worse then my old GTX 1080ti. What's wrong?


A few days ago I was running the simulator in my old configuration. Look:
Intel Core i7 8700K (stock)
Gigabyte Z370 AORUS Gaming 7
Corsair 16gb DDR4 3200 ram
GTX 1080ti AORUS Xtreme
ASUS ROG MONITOR - 2560-1440 - 144HZ G-Sync.

I ran the simulator with all the settings on ULTRA, at the monitor’s native resolution and had decent performance.
30 fps in cities and 70-80 fps in open places.

Strangely, the simulator only used the greatest potential of the graphics card when the camera was out of the cockpit. Inside the cabin the fps was low and the use of the GPU decreased a lot.

Thinking about improving the performance of the simulator I bought an RTX 3080 (ZOTAC TRINITY O.C.).

I used the DDU software to uninstall everything from the previous VGA and reinstalled all the drivers (Nvidia and monitor).

However, I did not reinstall MSFS.

All done, I realize that the performance has not improved at all. At some points it got worse.
I noticed that the luminous points, solar reflections and etc., were very bright and blurred.
Overall performance worsened, dropping around 10 fps in cities and 20 in open places.

What can I have done wrong?
Should I reinstall the simulator?
I always left G-Sync enabled. Should I leave it like this?
Thanks to all for your help.


You were most likely limited by CPU usage on the main thread, so I would expect performance to be about the same if you haven’t increased resolution or graphics quality settings.

Going somewhat down is a bit surprising, though.

Enable developer mode in options and check what the “display fps” menu item shows – what are your frame processing times on the main thread and the GPU?

Have you checked the new GPU is running on PCI x16 and not 8 also is the nvidia control panel set up the same?
One thing might be worth getting 32gb of ram as the sim will easily use more than 16 gb.

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Yes, it’s running in 16x!
More 16gb of ram is already on the way!


I did it.
Here some prints.

As you said, I’m MainThread limited. But… what does it mean?

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The game is wrong. I have stopped playing till they acknowledge how bad the performance is on high end systems and actually fix it professionally.


Limited by MainThread means your CPU is what limiting your FPS, not your GPU, so sadly the upgrade won’t do much if any good until that’s resolved. You can use the GPU better by increasing graphics settings (including render scaling if you really want to push it).

Your CPU has to calculate which parts the GPU has to render.
If MSFS is stepping up details because you now have a better GPU, your CPU will do more work and take more time to do it.
The performance of a single thread is important. The performance of the CPU and GPU should match. The 3080 is hight end. The CPU isn’t. Even a Ryzen 5600 X can reach its limits here.
Your CPU is not fast enough.
And here the gurte message: Further optimization in the future will probably reduce the demands on the CPU a little. But miracles cannot be expected.


i have almost the same setup :

Intel Core i7 8700K at 5.2ghz delided
Asus Maximus X Fomula Motherboard
Gskill 32gb DDR4 3200 ram 14cl
GTX 1080ti AORUS Xtreme
Asus ROG SWIFT PG279Q 160hz Monitor

On Thursday i expect the 3090 ( ASUS ROG STRIX GeForce RTX3090 GAMING OC 24 GB OC) to arrive and will send you my results.

i agree with all comments above, but try to overlock 8700k at higher frequencies, this CPU is still a beast.
At the moment based on developer mode i am GPU limited, and no issues with Main Thread.
Also for sure you need more Ram

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It looks like the 1080ti normally has 11GB VRAM while the 3080 has 10GB, so there shouldn’t be a significant difference in the amount of scenery detail that can be loaded into the graphics card at once; thus I wouldn’t expect the changed GPU to significantly alter how much CPU time is spent on scenery if no settings have changed.

Maxavila, you might want to double-check that everything’s still set the same both in the game and in the NVIDIA control panel.

Sometimes the GeForce Experience widget might try to change your game settings if you let it, for instance, and that might have changed something if you clicked in there after reinstalling drivers?

If you used DDU I’m pretty sure it will have reset to default any settings you had previously tuned in the NVIDIA control panel.

Make sure fxaa and mfaa are disabled for MSFS in the NVidia control panel as this was causing performance issue’s.

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get a new CPU. my 5800x is no longer bottleneck paired w 3080. my 3080 is 90-99% utilized and still get 35-60FPS on high settings in 4k.

maybe a PSU issue, newest powerful GPU need a lot of power supply…just a thought, hope it will help

Do NOT get a new CPU.

At 1080p a 8700k with 16gb should have a 5% bottleneck tops.

That is nothing. At 1440+ its around 1%

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BS. I had a 3700x before and went to a 5800x and now Im GPU bound and sim runs much better.

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He has an 8700k, not a 3700x and it is NOT BOTTLENECKED BY A 3080

You don’t have a clue what you’re talking about and doing more harm than good by “participating” in this discussion.

Go away.

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The sim bottlenecks at 1440p even on the cpu and I am on a weak cpu.My i5 8400 bottlenecks at 1440p in some areas my gpu is not fully utilized.
Normally 1440p is gpu reliant. Now I have to upgrade my cpu.

I say you dont have a clue what you are talking about. upgrade the CPU for better performance!

Therez not anything much better on the Intel side.