Long haul performance degradation back with SU12?

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Are you using Developer Mode or made changes in it?

No

Have you disabled/removed all your mods and addons?

No - using them to test long haul performance that was previously resolved pre-SU12,

Brief description of the issue:

During long hauls, performance seems to steadily drop. My flight today was from PDX-LSZH and at cruise after leaving Portland, my performance was upwards of 140fps. Over Scotland, my performance in the cockpit had reduced to 100fps at cruise. This was a bug we previously saw and it appears it may be back. By the time I landed I was down to 68fps. I’m fortunate to have plenty of head room with my system that 68fps is still not bad, but with a 4090/13900k, this is dismal compared to what I had leaving PDX.

Provide Screenshot(s)/video(s) of the issue encountered:

image
Different phases of the flight, you can steadily see the performance drop.

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This was after I reloaded the sim on the same runway where I had 68fps

Detailed steps to reproduce the issue encountered:

Long haul flights >6 hours.

PC specs and/or peripheral set up if relevant:

Intel i9 13900k - NZXT Kraken Z73 cooler - ASUS Maximus Hero Z790
32GB Trident Z 6000MHz DDR5 - Gigabyte 4090 GAMING OC 24G
10 x 120mm Lian Li UNI fans - Lian Li OD11XL Case - Corsair HX1500i PSU

Build Version # when you first started experiencing this issue:

1.31.22.0


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Do you have the same issue if you follow the OP’s steps to reproduce it?

Provide extra information to complete the original description of the issue:

If relevant, provide additional screenshots/video:

Do you have the same issue if you follow the OP’s steps to reproduce it?

Same as OP, complete any long haul flight (3-5+ hours) and you can watch the FPS diminish as the flight continues. The Apex of the issue is always on final / touch down.

Provide extra information to complete the original description of the issue:

SU11 / SU12 is when I noticed it.

If relevant, provide additional screenshots/video:

2 Likes

Do you have the same issue if you follow the OP’s steps to reproduce it?

Yes. During flight from Edinburgh, Scotland to Moscow, started capped at 60fps (my max framerate via NVIDIA control panel) and about 79% GPU usage, 19% CPU. By the time I was over Denmark it was down to about 48fps, and once over Latvia fps dropped to what seemed to be a capped 30fps. Once at 30fps, GPU usage showed 35% and CPU was only 11%. 30fps remained all the way until landing. Reloaded the flight back to Glasgow this time, and checked dev mode and sure enough, once again the “limited by main thread” issue despite an 19 threads worth of CPU waiting to be used.

Provide extra information to complete the original description of the issue:

Using DX12, 4k (via quality DLSS)

If relevant, provide additional screenshots/video:

1 Like

Yes this bug has returned, high usage at the start of the flight, Low usage at the end…

3 Likes

Yep, I’m seeing the same thing on my flights with the high usage that goes to low.

1 Like

I can confirm this. Long flights force high CPU usage and frame degradation.
I tested and confirmed it even over open water where the sim seems to have nothing to compute.

4 Likes

I’ve also noticed performance overall with SU12 seems to be less. Would you agree? I’d say around 15-20fps on average?

3 Likes

Having the same issue. For me it seems fairly randomly whether the degration happens or not.

2 Likes

fully agree on that!

same. did a test yesterday with a flight that was just under 9 hours in the PMDG 737. FPS were crawling near the end with huge pauses and stuttering. Disconnecting the autopilot for landing resulted in a CTD…very annoying.

1 Like

Same issue…I didn’t even fly, just left the PMDG 737 parked at KRIC for about 5 hours…crash.

1 Like

Do you have the same issue if you follow the OP’s steps to reproduce it?

Yes

Provide extra information to complete the original description of the issue:

Same as the OP. FPS decreases over time. The longer a flight, the more performance degrades. I’ve personally never experienced this before SU12.

If relevant, provide additional screenshots/video:

this post isn’t going to get the attention it deserves. Not enough people fly long haul due to lack of proper aircraft and time. So until the PMDG 777 gets released, this thread won’t get looked at :frowning:

1 Like

Don’t even need real long haul to see this in action. I’ve been flying the HJet a lot since SU12 landed. Typically flights are 90-120 minutes. I can typically see the performance start decreasing after about an hour of flight.

And that performance loss will get carried over to subsequent flights too. So now I have to restart the sim between flights to cancel this effect.

3 Likes

This has been a huge concern of mine and you’re exactly right. I think this got the attention of the right folks last time because people were just getting into the BBJ and testing out long hauls… that has kind of worn off and we wont see the uptick in long hauls until the T7, just as you said. I’m hopeful we’ll see some attention soon though.

1 Like

I’ve had lots of problems with SU12 performance wise.

Finally managed to get it to pre-SU12 FPS when I load in (albeit with significantly reduced MSFS graphic settings). But once in cruise (may be an hour into the flight), it reduces by ~20%. Find it much worse during daytime. Tried everything but no solution.

2 Likes

don’t worry, when aerosoft releases the 330 this thread will explode haha.

2 Likes

Is tgere any benefit to using DX12 ?

Absolutely - for anyone using a 40xx series card, you have to enable DX12 to be able to use frame generation which practically doubles your performance.

Remember when there was a huge problem with performance getting ever worse during the run because AI traffic never got garbage-collected or something? I wonder if that’s back, or something similar…

1 Like