I flew the Honda Jet from KSJC (San Jose) to Santa Barbara (KSBA) with FPS > 50 all the way to the Initial Fix on the ILS 07 approach.  At that point the FPS suddenly dropped to the low 20s.  During the landing on Rwy 7 the FPS stayed below 20 FPS.  I parked at the GA ramp and took a screen shot with detailed performance data shown. 

I shut down the simulator and then restarted it with the Honda Jet parked at the same KSBA ramp.  All the sim settings remained exactly as they were at the time I parked in the prior session with an FPS of 24.  But, after restarting the sim - the FPS was 46.

I have included both screen shots with all the performance data shown.  To summarize that data (all time is milliseconds) I have shown the difference between the two scenarios.  A negative time means the low FPS value is less than the High FPS value:

FPS 24.3  46.3
19.5 Total Frame time (Low FPS frame time is 19.5 ms longer than high FPS frame time)
 -3.0 Main Thread (Low FPS Main Thread time is 3 ms shorter than high FPS frame time)
  1.8 Rdr Thread 
  1.0 Manipulators 
   0.0 Coherent GT Draw
  1.3 Coherent GTUI Thread

The total frame time for the low FPS setting is 19.5ms longer but the displayed components are only 1.1ms longer than the High FPS. 
The total CPU Utilization for the low is 590% (out of 800%) compared to 563% for the high scenario.  It appears the CPU utilization is about the same for the two scenarios. 
The system memory usage for the low is only 0.8GB less for the low FPS than the 39.6 shown for the high. 

 -1.5 GPU (Low FPS GPU is 1.5 ms shorter than high FPS GPU time)
   0.3 GPU Compute

The big difference I see is that the low FPS scenario has the GPU (RTX 4070 S 12GB VRAM) at 66% load compared to the 99% for the high FPS scene. The GPU memory controller is only 17% busy in the low FPS with ~10GB VRAM in use compared to 31% memory controller usage and 10.6 GB VRAM in use for the high FPS.

The most surprising difference is that the high FPS main thread time is 17% longer than the low FPS main thread.  

The second curiosity is that the high FPS GPU time is 8% longer than the low FPS GPU time.  

WHY - sitting in the same location with the same settings is the FPS 90% higher in one scenario than the other? 

 

16 minutes ago, TacomaSailor said:

WHY - sitting in the same location with the same settings is the FPS 90% higher in one scenario than the other

The scenarios are actually quite different:  one is at the end of a flight out of complex scenery and the other a fresh start and no flight yet.  That doesn't explain much of what you're experiencing I know.  I fly in and out of KSBA quite a bit in the last month since installing 2024 and have not had any issues like that.  I have had bizarre starts of 2024 where perf was closing in on half of what is predicted and a reboot restart back to normal.

I've generally found FS24 to be very finicky. Similar to the P3D and FSX days, I'll often have to start a flight in a very basic plane to load into the airport, go back to the main menu and reload in my desired aircraft. FPS fluctuations have been similar to your situation, with no reasonable explanation...maybe it has something to do with the rolling cache...? I'm honestly not sure anymore.

Clearly in the first pic your GPU isn't being fully utilized for some reason 66% vs 98% so the question is why is your GPU utilization so different...  

I know this sounds funny but it looks like in the menu bar "HELP" is highlighted.  Could it be as simple as when you have a menu item open the GPU usage decreases?

Disregard, saw your post after mine which eliminates my theory.  Weird. 

Edited March 13, 20251 yr by psolk

4 minutes ago, Noel said:

The scenarios are actually quite different:  one is at the end of a flight out of complex scenery and the other a fresh start and no flight yet. 

Indeed!  That is the indirect issue I was aiming at.  This problem occurs in about 20% of my sessions.  I fly 30-minutes to an hour with complex scenery and FPS>60 and then on final approach the FPS dives to an unflyable level.  As you said, nothing short of restarting the sim will restore the performance, as measured by FPS, to an acceptable level.  This seems to happen only when I have a complex addon airport as the destination.  I primarily use ORBX addon airports and do recognize the load they place on the system.  

But, there is something fundamentally wrong with how FS 2024 manages resources in a complex situation.  I am sure Asobo/Microsoft has the instrumentation to track resource usage - here we are 5-months into the life of the sim and the situation is not improving.   There are ever more beautiful addons but it is a real disappointment when use of those addons brings a functional end to a flight sim session due to very low frame rates.  Trying to land even a 172 with <10 FPS is a trial. 

 

1 minute ago, V1ROTA7E said:

I've generally found FS24 to be very finicky.

I've had generally very good experience in terms of bugs per se but I am only using two default planes and so far have enabled only two airports from 2020 that seem to be okay, and one that wasn't so disabled it.  Not a good time to stress, test, push 2024 it's just not ready yet.  But fun to dabble in.  I am happy it plays well with Self Loading Cargo and APL.  After now about 30 flights in 2024 if I had to select only one sim for use now, no question 2020 wins.  I'm pretty sure 2024 will win that spot, just not now!  That being said I'm still very 2024-curious so am in it maybe 50% of my sim time already. 

2 minutes ago, psolk said:

Clearly in the first pic your GPU isn't being fully utilized for some reason 66% vs 98% so the question is why is your GPU utilization so different...  

You are correct.  In a normal situation the GPU utilization stays around 98% all the time and the FPS varies by maybe 10% from moment to moment.   My understanding is that the GPU only does the work requested by the CPU based code and it seems to me that if the GPU is not fully utilized then the CPU based code is not requesting/sending enough work to the GPU.   

2 minutes ago, TacomaSailor said:

But, there is something fundamentally wrong with how FS 2024 manages resources in a complex situation. 

Is it possible these are not native 2024 or have not been fully optimized? I know the two I just installed were tagged by the Marketplace Library as Streamed, !Not Creator Approved.   I've read some airports of comparable complexity are far better optimized than others so maybe that's happening as well.

Using VR I've been used to random FPS/Performance fluctuations in MSFS2020 for 4+ years, with MSFS24 it's a whole new headache and in my mind I can only point it to one thing; The Servers.

If they're overloaded (see practically every weekend) then FPS/Performance can vary in identical situations clear as day, sometimes its bad enough to just give up, other times for whatever reason it "settles down" after a few minutes and improves. All this without touching a single setting in or out of the game, whilst my 1gig broadband whistles a merry tune as it's running perfectly fine as well.

So what else could it be but the Servers? Perhaps poor optimisation of the codebase could also play a factor, something Asobo have long since struggled with, ultimately there's probably a million and 1 reasons why but when everything is identical my end then it can only be the game and/or servers at fault. Now having to rely on the Servers more than ever, that in itself just throws up more potential headaches when simply wanting to fly.

The situation is becoming truly annoying!

Just flew  from KSJC (ORBX 2024 compatible) to KTVL (south Lake Tahoe - an Asobo 2024 airport) with FPS > 75 all the way to the SAKYY (MDA  2.6 NM from touchdown) on RNAV (GPS) Rwy 18.  

The FPS then went to 20 and by the time the plane crossed the end of the runway the FPS was below 10 and flight control was almost impossible.  I am using Frame Gen so the actual FPS/Input latency was then >20 milliseconds. Landing at 90-knots means the plane travels 150 feet per second or 30-feet per input latency.  It is hard to grease a landing with that kind of latency. 

No addons were loaded other than KSJC.  The system is dedicated to FS 2024 and NO security or anti-virus is running.  I run system informer on a separate screen (9800X3D has 8 physical processors and can run 16 threads simultaneously) to verify there is no process or service using CPU/Network/Disk access at the time I am trying to land.  

It is discouraging knowing, during a flight that is working perfectly, that landing may not be possible because of this FPS drop.  

Edited March 13, 20251 yr by TacomaSailor