I've done some testing, but I'm not sure if this applies to others and can be reproduce. Basically, I tested time compression at different airports and regions. I almost always get 4x in Europe, while in Asia, it's consistently 2x—even when stationary at the airport. I have some images to show the time compression 4x/2x and just standing at the airport. I've attached a few screenshots below, but I tested in many more locations. In Asia, I tried airports like RJTT, RJAA, WSSS, and WADD, while in Europe, I tested EDDF and EGLL. Despite worse performance in some European airports, they were still able to reach 4x time compression. However i never achieve more than 2x in Asia. Can't say for other places such as US, Australia, etc. I only tested in those 2 continents
Another thing I noticed is that during a flight from LFBO to WSSS, at some point between the UAE and India, the sim rate drops to 2x while cruising and never returns to 4x. This happens despite performance remaining very stable, consistently reaching 140–170 FPS with frame generation at FL410.
The screenshot below is taken without any frame gen, most settings are on High, only sea traffic and clouds are on ultra.
PC specs :
Ryzen 7 9800x3d
RAM 64 GB 6000Mhz
RTX 4070 Ti Super 16GB
The images is compressed because of the file size limit, it may be not readable. I can reupload the original one if necessary.
EGLL from flightsimto gives the worse performance but able to reach 4x.
EHAM from Asobo able to reach 4x
WIII from Binersim only reach 2x
Same with ZYTL