I've always had fairly good performance in Flight Simulator, between 30 and 60 fps depending on area and flight conditions. 

Earlier this week I flew from LFBT (France) to LERS (Spain). Performance was good, everything was smooth. 

Then 4 days later I picked up the flight from LERS and flew to LEVC. The performance was abyssimal. I'm talking around 5-15 fps on the airport. I changed weather conditions to check if that was the cause, it wasn't. The problem only happened when I was panning the camera looking out of the windows. If I was looking down inside the cockpit only, no issues. The performance also got better when I was at altitude, but got worse when I decended to land. After landing I decided to play with the sliders, and what helped was lowering Terrain LOD from 100 to around 50. Then the issues were non-existant. Objects LOD made no difference. I've never had trouble with LOD before, and when I was at the same airport 4 days earlier no such issues existed. I was flying the same aircraft, the TBM 930 on both occations.

The weird thing is that I had changed absolutely nothing between the two flights. My computer had no updates, I did not update the graphics driver. I did not install anything or change any settings. Just went from 30-60 fps to 5-15 fps without any explenation. 

Have anyone experienced something similar? My GPU was running at 98% through the entire time, which is normal for me.

My specs: R9 3900X / GTX 2080 Super / 64 GB 3600 CL16 / System drive M.2 / FS drive M.2 / Localcache drive SSD / 3440x1440 60hz display

Edited October 10, 20205 yr by Republic3D
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Update:

I'm doing some testing at LEVC airport with the drone. 

Like I mentioned before, lowering Terrain LOD from 100 to 50 improved performance. Still some stutters.

Now the crazy thing: INCREASING Terrain LOD from 100 to 200 increases performance significantly! 

What's going on? Is there some issue with loading the terrain from LocalCache?

Edit: Now it suddenly tanked again... 

Edited October 10, 20205 yr by Republic3D
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Update 2:

I've now gotten it to run completely smooth with great FPS (45-60) even in urban enviroments at Terrain LOD 100. I took off from LEVC and landed at LXGB (Gibraltar) with the TBM 930, which was an awesome flight btw. The visual approach on left downwind Runway 9 around the Rock is pretty spectacular and the perfect amount of excitement! Gibraltar is modeled very well and Spain has a lot of photogrammetry. I pretty much nailed the landing on the first attempt.

What I did was:

- Updating to the latest Nvidia driver 456.71 (this shouldn't matter as it was previously working great on the previous driver).

- Downloaded MSI Afterburner, set Power to 105%, + 500 on memory clock and ran OC Scan. That created an OC Curve with +41 Mhz boost clock and I applied that. Saved the profile and set it to start upon loading Windows. This is my first time overclocking my GPU, but it went very well so far *knock on wood*.

The thing is, I don't know if what I did was the solution. Instead of poor FPS and full of stutters, it now stutters once for 5-10 sec when loading up the plane and looking around. Then completely smooth the rest of the flight, until approaching Gibraltar where there was another spike. But that happened about 20 miles out, so no issue. I'd rather have two spikes that than poor FPS. I believe the real issue is LocalCache and loading that. I have 400 GB on a regular SSD that I use for LocalCache. I have not changed anything with that. So this whole thing was a bit strange.

Edited October 10, 20205 yr by Republic3D