Confused about performance metrics in MSFS

[RaptyrOne 1,414]

I'm running an Intel i7-14700K and a RTX4070Ti Super. No overclock at the moment. When checking the Developer Mode FPS counter while buzzing around in Black Square King Air, the display is permanently in the green with "Limited by Main Thread". FPS is around 60-70 with most settings on Ultra and tLOD at 200. This is on a 144Hz 4K monitor running native resolution with G-Sync active and V-Sync on in NVCP but with no frame limiter.

Given that "Limited by Main Thread" means that the system performance/FPS is limited by the CPU (more specifically, a single CPU core), that would imply that buying a RTX4080 or RTX4090 specifically for MSFS performance would be wasting a chunk of money unless perhaps it was paired with an i9-14900K (or AMD equivalent) and possibly overclocked, to break the main thread 'shackles'. By my interpretation then, if I had splashed out on a RTX4090 with this particular CPU, I would have been royally wasting my money. Am I right in this logic? I suspect I am missing something? 

[MrFuzzy 2,118]

Yes, you are right. Even upgrading the CPU would not bring great benefits compared to the cost. Ideally a 7800X3D would give you maybe 10 more fps but would require a motherboard replacement. With a 14900K the improvement would be negligible. 

[jcomm 5,939]

They'll surely optimize it still along MSFS 2020 updating process and for MSFS 2024...

Even as it is right now it's, at the level of visual details it offers, probably the best performing general purpose flightsim I have ever used...

Edited March 26 by jcomm

[Cpt_Piett 4,695]

4 hours ago, RaptyrOne said:

Given that "Limited by Main Thread" means that the system performance/FPS is limited by the CPU (more specifically, a single CPU core), that would imply that buying a RTX4080 or RTX4090 specifically for MSFS performance would be wasting a chunk of money unless perhaps it was paired with an i9-14900K (or AMD equivalent) and possibly overclocked, to break the main thread 'shackles'. By my interpretation then, if I had splashed out on a RTX4090 with this particular CPU, I would have been royally wasting my money. Am I right in this logic? I suspect I am missing something? 

I have a 4090 and a 12900KF overclocked to 5.1GHz on all 8 P-Cores. MSFS is MT-limited most of the time, but usually that doesn’t result in stutters. It’s only when the MT is so hammered that native FPS falls below 30 that performance really deteriorates. In that case, the 4090 won’t save the day - you’ll get a stuttery 60 FPS, possibly combined with FG-induced artifacts. 

I.e. I (or rather MSFS) can be MT-limited and I can still get exceptionally smooth performance with almost zero frame time variability. 

For FG to work properly, native FPS should be above 30, preferably higher. Hence, the 4090 should be paired with a decent CPU. This does not necessarily mean the latest and greatest - mine is 2 yrs old now. 

 

Edited March 26 by Cpt_Piett

[Ixoye 1,822]

There is no CPU on the market that can handle MFSF today, I'm using AMD 7800X3D and i'm still in limited by main thread with the latest beta, so there is no hope, and I doubt that MFSFS 2024 will make any difference.
 A 4090 will give you all visual candy except AI and T-LOD, but I'm  running the sim with steady 97fps in Ultra settings, and i'm happy with that, even as i'm limited by main thread.

Edited March 26 by Ixoye

[orchestra_nl 935]

4 minutes ago, Ixoye said:

There is no CPU that can handle MFSF today, I'm using AMD 7800X3D and i'm still in limited by main thread.

And it might be always an issue. With faster CPU's we will just add more AI aircraft and more complex addons to fill the gap.
Better use of all the CPU cores would be great but in the end everything will need to come together in a single process which is the main thread. I am really curious if and how that is solved in MSFS2024.

[RaptyrOne 1,414]

Very interesting. That means I can sleep easy knowing I opted for the RTX4070Ti Super and not a very much more expensive 4080, let alone 4090. RTX4070TiS easily handles 4K with settings on Ultra and the [also high end] CPU is the bottleneck.

But then why are people motivated to buy the hellish expensive RTX4090 for this sim when the cost-vs-reward is off the scale bad? I guess using 2 or 3 4K monitors makes it justifiable. I can buy two RTX4070Ti Super's for the price of a single RTX4090. I guess in other applications/games it might be a different story. What this does highlight to me is that a bit of CPU overclocking might produce a small boost in sim performance. The i7-14700K runs at 5.5 - 5.6 Ghz but with a little under-volting and P-Core overclocking, seems it can easily run at 5,9 - 6,0 Ghz with good temps and stability. How that equates to FPS would remain to be seen.

[Ixoye 1,822]

19 minutes ago, RaptyrOne said:

Very interesting. That means I can sleep easy knowing I opted for the RTX4070Ti Super and not a very much more expensive 4080, let alone 4090. RTX4070TiS easily handles 4K with settings on Ultra and the [also high end] CPU is the bottleneck.

But then why are people motivated to buy the hellish expensive RTX4090 for this sim when the cost-vs-reward is off the scale bad? I guess using 2 or 3 4K monitors makes it justifiable. I can buy two RTX4070Ti Super's for the price of a single RTX4090. I guess in other applications/games it might be a different story. What this does highlight to me is that a bit of CPU overclocking might produce a small boost in sim performance. The i7-14700K runs at 5.5 - 5.6 Ghz but with a little under-volting and P-Core overclocking, seems it can easily run at 5,9 - 6,0 Ghz with good temps and stability. How that equates to FPS would remain to be seen.

24GB VRAM, thats your answer, I have a 3440X1440 monitor and I have seen 15.8GB VRAM usage on my 4090 at most, in 4k that would kill a 4070 Ti Super, and headroom is nice to have.

Edited March 26 by Ixoye

[Cognita 1,089]

I think the architecture ensures we will all be main core limited and I also anticipate this will be the same in 2024 because there has been no talk of a different architecture, just different features and changes to where content is stored and likely how it is accessed. It is better to put money into the best motherboard and processer one can afford, even if that means a slightly less prestigious graphics card. I have been eyeing the 4070TI super, which has 16 GB VRAM, but am generally trying to hold off until 2024 releases and I can see if there are any changes that would sway my decision.

The difficult decision for me will be whether to migrate from Intel, which I have used almost exclusively my whole life, to AMD. 

[Cpt_Piett 4,695]

1 hour ago, RaptyrOne said:

But then why are people motivated to buy the hellish expensive RTX4090 for this sim when the cost-vs-reward is off the scale bad?

Why are people motivated to splurge on a <insert any overpriced luxury item that nobody “needs”>

https://mises.org/mises-wire/capitalism-turns-luxuries-necessities

Let’s not start this debate again.

1 hour ago, RaptyrOne said:

That means I can sleep easy knowing I opted for the RTX4070Ti Super and not a very much more expensive 4080, let alone 4090. RTX4070TiS easily handles 4K with settings on Ultra and the [also high end] CPU is the bottleneck.

I’d say you should be able to sleep very easy ☺️ And some of us that got the 4090 for the sake of having the latest and greatest, are possibly feeling a bit regretful about that today. 

Quote

I should not be allowed near human currency. I've spent a hideous amount on my ultimate PC gaming setup, and occasionally, I’ve expressed regret over putting together such a rig. I can't deny I still adore my RTX 4090-powered monster, though. 

Before I big up the world’s most powerful consumer graphics card, let me prefix this recommendation. 95% of PC gamers won’t need anywhere close to the level of GPU grunt the Nvidia GeForce RTX 4090 provides. 

However, if you do find yourself rolling around in Scrooge McDuck levels of disposable cash and want the absolute ultimate graphics card, this is the GPU to power the best PC games in 4K at 120 fps and above. And in case you’re wondering, yes, my monthly credit card bill has become hella spicy ever since buying my 4090 around a year ago.  

https://www.tomsguide.com/opinion/my-dream-pc-gaming-setup-is-utter-overkill-but-i-love-it-anyway#:~:text=95% of PC gamers won,at 120 fps and above.

Edited March 26 by Cpt_Piett

[sniper31 639]

1 hour ago, Cpt_Piett said:

And some of us that got the 4090 for the sake of having the latest and greatest, are possibly feeling a bit regretful about that today. 

And some of us are absolutely NOT regretting buying a 4090 😊😁. Mine has been great and I have been getting my money's worth out of it. It pairs really well with a 7800X3D and my sim and PC are NOT main thread limited. With the 4090, you have a lot of room to play with the settings within MSFS and the Nvidia settings to get a good balance between CPU and GPU. I run in 4k on one screen, fly mostly the Fenix A320 and all is smooth and nice. I run locked at 63 on my 144Hz G-Sync display and I don't use any auto fps apps or t-lod apps. I am not doing anything weird with my settings, no secret sauce. Just MSFS and Nvidia, a 7800X3D, G-Sync display and a 4090. I have no performance issues to complain about. 

[RaptyrOne 1,414]

5 hours ago, sniper31 said:

. I run in 4k on one screen, fly mostly the Fenix A320 and all is smooth and nice. I run locked at 63 on my 144Hz G-Sync display and I don't use any auto fps apps or t-lod apps. I am not doing anything weird with my settings, no secret sauce. Just MSFS and Nvidia, a 7800X3D, G-Sync display and a 4090. I have no performance issues to complain about. 

Yeah but this comes back to my original thought. I also run a single 4K monitor 144Hz with G-Sync and can (more or less) max out graphics settings and maintain liquid smooth 60+ FPS. On a RTX4070Ti Super. So if my GPU is waiting on the CPU, I imagine your RTX 4090 is hardly awake, let alone breaking a sweat.😁 if you are not main thread limited tho, what does the FPS counter show as the limiting factor in your system?

[sniper31 639]

1 minute ago, RaptyrOne said:

Yeah but this comes back to my original thought. I also run a single 4K monitor 144Hz with G-Sync and can (more or less) max out graphics settings and maintain liquid smooth 60+ FPS. On a RTX4070Ti Super. So if my GPU is waiting on the CPU, I imagine your RTX 4090 is hardly awake, let alone breaking a sweat.😁 if you are not main thread limited tho, what does the FPS counter show as the limiting factor in your system?

I have it tuned so that it bounces back between CPU and GPU limited. My GPU typically runs more around 50% on a typical flight, and my CPU is being used around 42-45%. I am also running a fair amount of AI traffic and GSX if that matters, plus I fly into and out of a lot of the iniBuilds airports that other simmers complain give them stutters, which on my system I don't have a problem with. Lastly, my system temps are around 52-55C while simming. Granted, I live in Colorado where the temps are very cold to mild most of the year, and my PC is in my basement which is nice and cool. But I have also built my machine for maximum airflow and it is cooled with AIO too, so that all helps. The final result is a sim PC that runs nice and cool, very efficient and MSFS performs very smoothly on it as detailed above. 

[Cpt_Piett 4,695]

19 minutes ago, sniper31 said:

My GPU typically runs more around 50% on a typical flight, and my CPU is being used around 42-45%.

Very similar here. If I crank up the resolution to "5K" however, the 4090 is running at a constant 99%. 

[sniper31 639]

1 minute ago, Cpt_Piett said:

Very similar here. If I crank up the resolution to "5K" however, the 4090 is running at a constant 99%. 

Yes, same here when I experimented with that resolution. I could run most places just fine, but there were some bigger, busier airports at that resolution that were a little stuttery, so I decided the resolution wasn't worth the tradeoff in performance, especially when 4k looks so good.