Certain Trees lowering my FPS

First of all 200 Terrain LOD is going to kill your performance around KATL. The entire surrounding area is overwhelmed with large trees to hide the hideous photogrammetry spike trees and combing that with high LOD would put a strain on any PC.I have to turn my LOD down to 100 to make things smoother when taking off and landing in at ATL but having the camera face the trees my fps drops in the teens.
To me its the worst optimized area in the sim and was just left there hanging.
Other areas like NYC,LAX I can bump it to up to 150-200.

You get the idea from the screenshot and this is not even 4k.

LAX also photogrammetry but way less trees

For me, it’s a specific type of tree, on the east coast, that kills the frame rate. It causes RAM usage to spike while it’s slows down the FPS. After passing the trees, it takes some time for RAM usage to drop and speed to resume normal.

I can fly over an entire forest of other trees and be fine.

I’m thinking there’s some kind of glitch with that specific tree design that saps performance.

I suppose photogrammetry “trees” can be part of the problem as well

Yep flying a very dense forest no issues with fps drops.

I’ve also seen specific areas slow down, generally parks in or near large cities in photogrammetry areas. Big slowdown when flying low, gets worse as get closer/lower. Gets better as fly away.

Examples:

  • New York - Central Park
  • San Francisco – the little chunk of park on the northwest corner of the city (this area seems worse than Golden Gate Park, which is affected as well but not as badly)

I haven’t double-checked them on the latest release, though.

I wonder if anyone at ASOBO has reviewed this issue although I sent this issue to their zendesk several times.

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I have about 25 FPS with my settings at the ground at KATL, some drops to 20 shortly after takeoff which goes back up to 25 (or above) while flying to the northeast past Atlanta at 3000ft. All in cockpit view in the TBM. That is fine for me as I am not in photogrammetry areas for longer periods of time.

I would expect FPS to stay in that range while in the general area. However, FPS gradually drops lower and lower the longer I stay in the area and never really recovers, even after restarting the flight. This does not only happen in Atlanta or the US east coast, it just occurs there a lot faster. I also had that some weeks ago (also after the tree render distance patch) on the west coast in a non-photogrammetry area. However, I was taking of from a photogrammetry area and flying into mountainous terrain with dense tree coverage where the same gradual FPS drop occurred within 20 minutes from above 30 to below 10. I don’t remember exactly where it was. There were also a few other occurences of this issue on longer VFR flights. I believe all of them were in the US.

Adding to my previous post, I did some more experiments in the KATL area: With photogrammetry disabled and without the tree removing mod, I don’t see FPS progressively getting worse. Lowering terrain LOD has the same effect, as does having photogrammetry enabled and trees disabled via mod.

Apparently, the combination of high terrain LOD + lots of photogrammetry details + lots of generated trees triggers the progressive performance drop I’m seeing very quickly. I would expect consistently low FPS in this scenario or some occasional drops due to varying grades of detail in photogrammetry data, but not the sim slowly turning into a slide show (except if RAM is full which it is not).

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Its a pity I don’t have another GPU to test. Would love to know the results with something like a 3080/3080ti.Waiting on Best Buy to see if I can beat the bots just for fun instead of joining a long line.
Other optimization a faster card should bump the performance up in that area.

Best of luck beating the bots then. I did my tests on RTX 3090 + Ryzen 5950X. Does not always feel like it with these kinds of issues. :wink:

From what I can see going down to 1080p I do not get fps drops with trees and my fps is in the 30s when looking down at the trees. My native resolution is 3440x1440 and its probably too much for the 2060super to do dropping fps to 16 instead of the 35 I get on 1080p . It has to be a GPU bandwidth limitation at least on my end.
I added a 3080 and 3070 to cart on Thursday .When I did a refresh they were gone. 3090s are going for 3000$.Dang enough to pay for an entire new rig.

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You hit it on the head
I think we have the same exact issue.
Have you flown over the forests north east of Central park [around KDXR airport]? The same issue persists but goes way once the trees change from dark green to light green.

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As you may recall, I experimented shifting from a 3070 to a 3080. It allowed me to move one performance bracket up @ 4k. From medium to high, in relation to this tree problem.

I came to the conclusion that the tree issue resulted from memory bandwidth limitations because it wouldn’t as readily dump to ram with the graphic card upgrade

Outside the problem tree areas, the 3070 handles high and 3080 handles ultra, at 4k, very well.

Same performance issue around Pittsburgh with similar trees. I am curious to see how they did this area on the XBOX and what the performance is like.

Trees have had a big impact onf FPS after SU4. ASOBO informed that they reduced the size of the trees but added more trees to maintain coverage. Maybe this is the reason why we have had this impact on FPS since SU4 in regions with lots of trees.

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This has been an issue long before SU4.
It’s just now common in more places

Hmm… I have noticed it only after SU4. I usually fly at the same airports an now I have had a big impact on some airports that have a lot of trees around… Before SU4 the impact on FPS was much less. Frames went down from 47 to 37, 38 at some of these airports…

I noticed no specific change with SU4. Always had this problem.

Lemme check…

No, I get a solid 40 fps in the C172 steam gauge, and there doesn’t seem to be any photogrammetry nearby so I don’t think it’s related.

(This is way outside Manhattan, so I wouldn’t really consider it northeast of Central Park)

If I head towards Manhattan, around KHPN the photogrammetry for the New York City area starts, and fps drops from 40 to more like 32, which is expected. No extreme drops.

Up to 35fps or so closer to the water.

As high as 38fps approaching the city.

Down to about 32fps near/over Central Park.

If I lower to about 300 feet altitude, it gets down to 25-28fps.

This is actually a HUGE IMPROVEMENT since I last tested it!

As far as I’m considered this issue is 90% fixed.

Thanks for pointing out the location discrepancy. It appears that I gave the wrong directions. The airport should by Westchester county Airport… which I think it KHPN.

So here’s the funny thing, sometimes the performance in that area AND central park is solid on my machine. The problem is not consistent. Try turning on your cache and flying with a turbo prop plane… make a few passes. Usually by the 15 minute mark is when the FPS drops. Also cycle from cockpit and external view at least once

I also want to point out that hwinfo does not report thermal throttling at any point

I’ve been dealing with this specific tree issue since 2020