Is the Intel i9 10900k not powerful enough? Limited by Main Thread

Hello, in 2020 after MSFS came out I built a new PC with an intel CPU i9 10900k and Nvidea 3090GPU. now two years later the sim runs ok with add-ons like the Fenix a320 in JFK or using airport addons like Aerosoft Brussels I get an average of 24/28 fps on the ground, it’s fine it feels fluid but still I thought I would get more. DLSS does not improve and I believe is due to CPU bottleneck as when I check the fps it constantly says Limited by Main Thread and I think the 3090 cannot go full power.

I read that people switching to the Intel I9 12gen managed to get 60fps therefore I am wondering if I get a 13gen i9 will I finally be able to land in the heavy airports with the Fenix 320 with fps not dropping below 30FPS? I will also take a DDR5 MOBO but still use the 64gb RAM DD4.

Any thoughts? thanks


A couple of thoughts. First, you can’t buy a DDR5 MOBO and use DDR4 memory, so don’t try that :slight_smile:

Second, I use a same generation i7-10700 and am primarily limited by main thread, and around 30fps with a complex plane at a busy airport.

You can try turning down TLOD a bit or turning traffic down with something like FSLTL and you will get a bit better FPS in those areas, but if you don’t like that, your only option is a more powerful CPU.

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The AMD 5800X3D has been shown to give the highest FPS in MSFS, directly attributable to the larger cpu cache.
An updated 7xxxX3D version is due in the next 2 - 4 months.
Personally (i9-9900k) I am inclined to wait to see what that can do.

Hi thanks for the info at one shop it was saying that on the asus strix mobo I can put ddr 4/5 but I can’t find the same info on the asus main website.

I am still figuring out if it worth the upgrade but to be honest I am avoiding busy airports I can’t stand the drop in FPS during approach.

I just don’t want to upgrade and still face performance issues! I thought with the rig I’ve built that I would be fine.

It was the case with default aircraft but now with more complex addons I feel to upgrade the Intel 13th Gen they are saying that is very powerfull.

I might sell the old Mobo 64gb ram and the CPU and I might make some bucks back maybe.

DDR4 and DDR5 use physically different slots, so unless the MB has both this can’t work. Socket 1700 boards with the Z690+ chipset can take either type of RAM, but each MB model only supports either DDR4 or DDR5. I have not seen any motherboards with slots for both, as there just isn’t room. So you would have to choose at purchase time whether to go for an MB that takes DDR4 and stick with it, or upgrade both MB and RAM at the same time.

I would advise the latter as DDR5 has definitely sped up my system. That’s anecdotal data, of course, but it does remove a bottleneck.

Agree with the comments re TLOD, BTW. I am GPU limited almost all the time and my CPU cores are not generally pegged at 100% anywhere, but if I turn TLOD up past 100 that starts to change. At TLOD 200 in areas like London and NY I start to become CPU limited and FPS drops and stutters begin. I’m personally happy to exchange TLOD 100 for stable FPS but I know not everyone feels that way. This is on a 12900K, BTW. 13th gen will improve the situation but probably not that much.

Also, I’ve said this on other threads but there is no such thing as a system that will perform brilliantly in all scenarios. This sim is absolutely capable of bringing the highest-spec system to its knees and it always will be, especially when 3rd party add-ons can be much more demanding than the stock scenery and aircraft. It will always be a question of tweaking settings to get what is, for you personally, an acceptable balance. If you value consistent and ‘high-enough’ (whatever that means for you) FPS on final approach above other things, and you want to fly into complex and dense scenery in complex aircraft, then be prepared to sacrifice visual quality and other settings in order to get it. There’s just no getting around that.


I understand, I tweaked TOLOD so at the moment the sim is optimized. Don’t get me wrong its enjoyable but as I said I avoid using busy airports.

At the end I should buy the CPU, MOBO, DDR5 Ram at least so feels almost like changing PC.

My graphic settings are optimized I feel the only changes I could do is the hardware

Even with a 13900k, you will likely be mainthread limited when using terrain LOD above 200.

I set TOLOD around 100 and 200 depending of where I am flying at 150 I am happy. Being able to run at 200 would be good. What I am just looking for is to have FPS to not dropping bellow 30 in busy areas like NYC, 4K Ultra with addons like the Fenx.

Also today I was in Tromso using orbx scenery avarage 26 fps in the cockpit with the Fenix a320.

I am just wondering if there will be a processor able to handle MSFS?

Anyone using the 12th or 13th gen Intel? can DLSS help?

I’ve read very good things about the 13th gen I9 but I will look at it my last AMD pc was a very very long time ago, I usually go for Intel and Nvidea

I have a very similar set up to you, built around the same time but with a 3080 rather than 3090. 10900k i9, 64gb ram

Like you I’ve been thinking about an upgrade, but by the time i replace the motherboard and memory to ddr5 (feels like sticking with ddr4 would defeat the object a bit) and a 13900k, we are getting quickly into £1200 - £1500 territory.

At least you’ve got a 3090 - my fear is that I find the 3080 becomes a limitation if i did upgrade!

My system feels pretty balanced and i get good performance without stutters. I don’t track FPS too much but its around 30 most places with the Fenix and a little more with the PMDG 737.

I can live with it and prefer to push TLOD to 300 even though that does impact FPS quite a bit.

Also note I’m on 2k not 4k. On 4k i think i would struggle to get anything playable.

Yes pretty much the same price in swiss francs 1600, i9 13th gen, Asus Strix z790 F, 64GB ddr5 memory and 1000W PSU, because I feel 850W might be just the limit.

In the beginning, I thought I could put DDR4 and 5 in the same MOBO at least I would have saved 300 francs but yeah better go for a faster memory.

If I decide to upgrade I will try to sell the old components altogether so I can cover some of the cost maybe.

In another post, I read about a simmer upgrading to an I9 12900K from a 9900k and got rid of the bottleneck using a 3070, also avarage of 30/35 fsp landing in heavy airports.

What about i7 12700K and more than 60FPS? :wink:


MSFS Ultra settings,2k, i7 12700K @5GHz Pcores, RTX 3080, 32GB ram DDR4
motherboard MSI Z690 A DDR4

No need DDR5 - waste of money.

Thanks! depending on how my bill with the dentist will be later today I might upgrade xD

I made my mind anyway so this month or the next one I will upgrade.

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I’m planning on buying a new i9 13900K.

Hey guys managed to install all the new components. I must say the since I run the i9 13900k with ddr 5 32gb ram stock speeds I’ve got a boost of around 20 fps on the ground at addons airports I get around 45 fps with some spikes to 51fps, running 4k almost everything in Ultra of course onboatd the Fenix 320 in JFK default airport with fstl live traffic I get around 33 on avarage. The difference is amazing way more fluid!

I will complete the upgrade with 4090 anyway later in december!

It was worth the upgrade to be honest! And I think if you want result in 4K you need to go at least I9 12900 or above this are the cpu that can finally run the game


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I think it’s safe to say you’ll have the same issue no matter what CPU you use.

I just upgraded to a i5-13600 with 32GB DDR5 6000Mhz and at Chicago O’Hare (KORD) (probably the most demanding airport I’ve come across) the frame rate drops to low 30s.

Reducing TLoD makes a difference of a few FPS but nothing major. And I’ve tried both DX11 and 12.

I’ve seen videos on youtube where the 12900K has the same issues, I don’t think the 13900 will fare much better either.

Which leads me to think it’s an engine optimisation issue.

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Sounds good! Out of interest what do you get at O’Hare airport? :slightly_smiling_face:

At 4k it’s the GPU that comes into play. On the ground at airports it’s the CPU.

Those benchmarks you see like the one posted above are averages and won’t give an indication of frame rates on the ground if that’s what you’re after.

At 4k I get 70+FPS in flight with my 3080, but it’s when you land and taxi that bothers me, as I really notice the juddering at below 40FPS at large airports (my monitor’s VRR only works above 48FPS).

I have a 12700k and a 3080ti and I am mostly MainThread limited.

FS2020 ,like any game, is main thread limited.

You can throw a 64 Core/10Ghz CPU at it and it still will have one main thread that will function as the conductor of all the processes performed by itself and all the other cores.

I think O’Hare has really been hit by the AI changes (improvements?) in SU11. Using in sim injection with real-time online traffic, the gates almost completely fill up and all of that traffic kills my FPS. The already CPU intensive A310 brings my system to around 15fps.

i7-10700, RX 6800XT, WQHD.