lag FPS Dropping Throughout Flight

[gal-m 4]

Hey all,

 

pretty much what the title says. I will do a flight from point A ---> B and my FPS will gradually start falling, especially at "the end" (approach & landing). However if I exit the game and load back into the destination (or departure) airport, with all of the same settings as before, my FPS is once again "normal".

 

Let me give you an example:
I did a VERY short flight (only about 1hr - keep in mind the FPS drop is similar during much longer flights) from LJLJ (Ljubljana, Slovenia - Scenic Routes) ---> LKPR (Prague, Czech Republic - Tailstrike Designs) with the PMDG 737-800. I have a very nice system (5900X, RTX3090, 32GB RAM, 980 Pro, etc. etc.). 

Anyways, I started with 48 FPS (I have V-Sync enabled and my frames locked at 33 % to avoid conflicts due to a G-Sync monitor) and landed with only about 24ish. After shutdown I decided to disable FSLTL traffic to see if I maybe just need to restart FSLTL Traffic. The FPS only went up to about... 30ish. I then proceeded to close the game and launch it, spawn back in with the same weather, settings and mods (yes, even FSLTL was active), and was getting 46ish FPS.. 

Basically, I'll usually be getting anywhere from 60-70 FPS with my FPS unlocked and then it drops to anywhere from 40-50 FPS with FSLTL Traffic (for most bigger airports), but never bellow 30 FPS. I try to configure my settings this way, but obviously I don't do hundreds of test flights just to see what kind of drop I should really expecting.. 

 

Does anyone know how to mitigate this "issue"?

 

 

 

MODS (in this particular case):

• PMDG 737-800
• Scenic Routes – LJLJ Ljubljana Joze Pucnik Airport
• Tailstrike Designs – LKPR Vaclav Havel Airport Prague
• FSLTL Traffic
• FSRealistic
• FS2Crew PMDG 737 SOP 1

Other apps open during flight:

• Navigraph Simlink
• SimToolKitPro

[charliearon 3,025]

Now you are in the proper forum for your question!

[Tony P 160]

 

[gal-m 4]

Hey @Tony P, I really don't like editing the registry, not to mention the creator of the video doesn't even know what he's talking about - here:

 

Not sure why I can't paste screenshots here but I'll copy some of the comments from the creator of the vid:

• "Hello! I think this helped me because after like 2-3hrs, I used to lag hard but I think it’s better now. I think it’s because of that registry change from 2 to 4. Do you know what exactly that does? I’m interested. But thanks!"
• "That's great to hear .. honestly im.not to sure what the registry change does something with Microsoft communicating I'm not to sure . Thanks for the comment"

and

• "Thanks for your videos - always awesome! I sadly miss a bit the explanation of WHAT we are doing in the registry! What exactly are we changing there? Which system does this affect? I´m quite skeptical to change stuff in the registry without knowing what I´m really doing! Thanks! :)"
• "Hey thanks for the comment . The registry tweak I want to be upfront this doesn't help everyone only those with this very specific issue with MS trying to communicate while in the sim this causes stutters and also on long haul flights with the fps spikes but again this doesn't help everyone for instance I don't experience those issues so for me this does nothing for me but you can always change it back if you find it doesn't help you. The tool I show makes more of a difference for me ."

 

I find it kind of funny that he doesn't even know WHAT he's tweaking and why. There are also people commenting that they are getting "less stuttering" when in reality I can guarantee that it's probably just placebo (if you're running on a decent system). These types of tweaks would need to be properly tested - aka benchmarked. Unfortunately the suggestions in this video only seem like hear-say..

Edited April 13, 2023 by gal-m

[Tony P 160]

ISLC is what you may need to fix your losing FPS over time issue.  You can ignore the NDU tweak.

[gal-m 4]

4 hours ago, Tony P said:

ISLC is what you may need to fix your losing FPS over time issue.

Thanks @Tony P. I might give it a shot tomorrow!

[Noel 4,507]

On 4/13/2023 at 10:47 AM, Tony P said:

ISLC is what you may need to fix your losing FPS over time issue.  You can ignore the NDU tweak.

ISLC?

Ahh, looked it up.  Is this primarily going to come into play when VRAM is getting close to maxed?

Edited April 14, 2023 by Noel

[gal-m 4]

11 hours ago, Noel said:

ISLC?

Ahh, looked it up.  Is this primarily going to come into play when VRAM is getting close to maxed?

Yeah... I got 24 GB of VRAM and 32 GB of RAM and after reading about it and testing it out it's most likely not going to help me since it's not getting saturated

[GSalden 4,679]

Using ISLC on both of my MSFS pc’s…

[gal-m 4]

1 hour ago, GSalden said:

Using ISLC on both of my MSFS pc’s…

Hi @GSalden, did you notice a difference?

[jrw4 624]

Rather than making changes to somewhat obscure registry settings has the OP tried the usual debugging techniques? It might help if we started out with a clean Community folder other than the PMDG product and try a flight that way. Is the same effect seen? What about at less demanding graphics settings? My own system is far less capable than that specified by the OP, but I don't see performance problems of the sort reported here.

BTW, I know that what I am about to say will not be popular, but I use the nVidia Gerforce Experience app to advise on the optimal graphics settings for my system and follow its recommendations to create a starting point for further tweaking. Seems to work fine. I also use Vsync to lock the graphics output to my monitor. No tearing and smooth frames with minimal stutters. One thing I don't have is custom airports, but that was also true for FSX, P3D, and XP. IMO, more trouble than they're worth. Others will feel differently, I'm sure.

[GSalden 4,679]

4 hours ago, gal-m said:

Hi @GSalden, did you notice a difference?

The inky thing that I can say is that I do not suffer from stutters ….

[Brandon01110 407]

FSLTL was the problem for me with fps degradation.  I havent had the problem after not using it.

[gal-m 4]

10 hours ago, GSalden said:

The inky thing that I can say is that I do not suffer from stutters

That's interesting @GSalden. For some reason my sim is actually completely stutter free, which is why I really don't like to use applications that are supposed to make MSFS perform better...

[gal-m 4]

6 hours ago, Brandon01110 said:

FSLTL was the problem for me with fps degradation.  I havent had the problem after not using it.

word not allowed... that's really quite sad to hear @Brandon01110, as I very much enjoy using FSLTL... Like I said above, my sim actually runs smoothly (without stutters) - the only issue really is just the consistently low FPS over time..

Did the performance degradation happen over time or instantly in your case if you still remember? Either way I'll try disabling FSLTL