Linear FPS Degradation with Time : Possible Memory Leak (1.18.14.0)

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-Nothing in the community Folder.

-Dev Mode is on but issue is present when Dev Mode is Off.

The Issue

Whenever I fly (or just sit on the ground), FPS decreases gradually over time, making long hauls and long flights impossible.
Emphasis on Time: I sat on the runway for 5h straight and had the FPS drop.
This issue happens with the B787 and the A320 at least, haven’t tested on GA Aircraft.
The only way to fully recover the FPS is by restarting the sim.

I tried :
-Disabling the ATC window
-Disabling the VFR Map
-Looking away from the instruments for a couple of minutes
-Using ISLC v1.0.2.2
-Disabling fullscreen optimisations
-Enabling/Disabling GPU Scheduling
-Enabling/Disabling Gamemode
-FXAA/MFAA are off in the NVidia Control Panel
-Excluding FlightSimulator.exe in the windows defender scan settings

Nothing has worked.

This is just after starting the flight, 30FPS:

This is 5h later…20FPS:

Now interestingly, sometimes when I pop into the menu and back in the game again, it freezes and I have some FPS recovery, sometimes 100% of FPS back, sometimes just a certain percentage back. This happens also when I go into windowed mode and back into fullscreen. Sometimes, the recovery doesn’t happen at all…

GPU usage goes down, but I don’t know if it is because of the CPU or not. I don’t know if it is memory, it is not full, pagefile is large enough and hard faults are rare and when they do happen it is 2/3 hard faults per second.

Interestingly, when going back in the menu, GPU usage goes back to 100% or near 100% like at the beginning off the flight:

This is after a freeze after going back to the game from the menu, something changed in memory and there is a small FPS recovery:

And these are my CPU temps, showing it is not thermal throttling:

PC specs

GeForce RTX 2060
Driver version 461.92
Intel Core i7-4790K CPU @4.00GHz
16GB DDR3 RAM @1600MHz
1TB SSD Samsung EVO 860
Oculus Rift S

Zendesk ticket #

96357

Seems like a puffer doesn´t get cleared… I´ll have an eye on your topic, will follow you.
Fo me it soemtimes feels like the same. but I just have flight with max. 2 hours.

I don’t think it is the same issue at all. The fps degradation happens everywhere on earth.

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Normally I don`t have any FPS-related problems in any game with my computer, especially not after the Ryzen Zen 2 update. (+32 GB of the fastest CL14 RAM, and the Flight Sim on a Corsair Force MP600 with 5000MB/sec transfer rate installed, always at least 50GB free on the SSD where Windows is installed).

But Flight Sim indeed sometimes has an FPS drop over time, but that does not take hours - sometimes the drops begin after 20 or 30 minutes of flight.

For example I start in New York or Tokyo with a very solid 30FPS frame rate which is really good in huge cities… and after 15 to 25 minutes of flight or so, not always but in many flights, over time everything becomes laggy and starts to stutter, the camera around the plane is no longer moving in fluid motions but stutters around the plane.
When turning around and flying back to the airport I came from, the approach and landing has only 17-20 frames plus noticeable stuttering when panning the camera around in the cockpit.

This is not a graphics card related issue but feels like if it has something to do with caching and reloading scenery speed… the stutters and performance slowdowns are not always happening, but when they happen it sometimes happens after 20 or 30 minutes of flight and it feels like suddenly operating a computer with a completely filled up SSD 0MB free space left… You know what I mean.
It`s not a graphics problem. :wink:

Probably a faster SSD might fix this problem, but there aren`t any SSDs available faster than 533MB/sec and an operating system does not boot from an NVMe.

1 Like

I tested with 1.14.6.0, the FPS drop is still there (granted it seems less intense than in 1.14.5.0) :

After flight start :

After 8 hours :

After sim restart :

I saw no parameter change in the HWiNFO.
Why is it “GPU limited” when the GPU is not at 100%? GPU temperature was 76°C.
I notice an active memory increase, although I just sit here on the runway doing nothing, why would memory increase? Memory leak maybe?

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In order not to be limited, you have to disable any framerate limiter and set Vsync to off.

I don’t have any framerate limit and vsync is off unfortunatly, plus I’m in VR so these settings aren’t even available

Okay, this is insane, I made another test to see what the performance was like after 5 hours, then :

Absolute disaster, but then I went in the menu, turned off and back on multiplayer, there was a freeze, and now :

Along with memory being freed, again.

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I was wondering about this for a while. On longer flights, more than 2 hours usually, the performance always drops - all over the world, even in the middle of the Sahara desert. I just finished the 3-hour long flight and it was very stuttery on the approach. When I finished the flight I closed the sim, loaded back in on the same approach, same weather, time, everything, smooth as silk.
I’m experiencing this for some time now.

2 Likes

I’ve seen it also. A couple days ago I was just sitting at Heathrow, frame rate report on, and ended up chatting with a couple friends on discord. Started at 62+ frames, and I watched it slowly drop to 40 over about a half hour. Same scene, plane not moving.

Interesting you noticed that turning multiplayer off and on again reset things. Good catch!

You should put that in as a bug report related to multiplayer. Maybe they’ll fix it in SU42 someday.

1 Like

I’m not using multiplayer.

I’m nearing the end of a 2+ hour flight. My frame rate has increased from 25 to 30 over that time.

So you don’t have this issue. Good for you.

It’s pretty random, I think I just got lucky, because I tried turning multiplayer off and on another time and it didn’t work. Sometimes you gotta change something, like go to external, go in the options, change some options, go to windowed and back to fullscreen, and sometimes when doing that the frames will recover fully or partially, most of the time only partially, so yeah it’s really weird

Still. I’m gonna try your discovery next time it happens to me.

Does this happen with dev mode on as well?

yes. As you can see on the screenshot I posted dev mode was on to monitor fps :slight_smile:

2 Likes

Hello everyone,

as there are multiple topics on this issue,
this topic is beeing closed.
This should prevent the splitting of votes and it may help in finding a solution.
Please continue here and recast your vote!

Thank you.