GPU performance discrepancy - "Discovery" flight vs "World Map" flight

Hello, I am new to the forum, and I would like to share an interesting observation I have made. I couldn’t see any other mention of this elsewhere in the forum or online.

I noticed this since playing around with SU5 yesterday. When I launched a flight from the “discovery” flight menu, the performance of the game was much smoother and more consistent vs launching a flight from the world map, even when flying in the same location, so I did a little investigation. Here are the two scenarios (all graphics settings on Ultra preset):

"Discovery" flight
I launch a flight from the discovery flight menu to Bora Bora island, monitoring GPU stats in MSI Afterburner, CPU threads in task manager

  • FPS is a constant 80-90, dipping to 70-80 when directly over / looking at the forested area of the island, dipping below this when panning the camera, as assets load in
  • GPU usage remains high, 98-100% throughout, dipping when panning the camera, as assets load in
  • Several CPU threads appear highly utilised, around 60-70%, topping at 100% in spikes.
  • Frametimes are generally low, game appears smooth and playable
  • I can slew the craft to a completely new location, and observe pretty much the same behaviour, the framerate will vary on the environment, but the GPU appears to be well utilised in any case.

"World Map" flight
I launch a flight from the World Map menu, in an approximate location to the discovery flight, and with similar weather conditions. AI & player traffic are turned off. monitoring GPU stats in MSI Afterburner, CPU threads in task manager

  • FPS is considerably lower - averaging around 55-65, with dips in the mid 40s
  • GPU usage now averages 65-75% (power consumption reduces as well)
  • CPU threads appear under-utilised, look to be in the 30-40% range, not really going above 60%
  • Frametimes are higher, and are more erratic

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The performance disparity I have noted above appears to be much more marked in high-load scenarios, such as cities: in world map flights, CPU usage will go up a little bit (but sitll not maxing out), but GPU usage will remain low, even going below 50%. FPS is even worse, usually averaging 25-30.

My best diagnosis I can think of is that the sim is not demanding a ‘high power’ state from the PC when entering world map flights. I have fiddled around with all manner of settings to try and fix this: VSync, Windows Game Mode, GPU scheduling, preferring high performance mode in NVidia Control Panel, and more, but nothing seems to change the disparity.

Can anyone comment on this - have you observed the same behaviour from the sim, and do you know what could be causing it?

My PC spec, if it helps:
CPU: AMD 5800X
GPU: NVidia 3080Ti
RAM: 64GB Dual Channel DDR4 @ 3600MHz
OS: Windows 10 21H1 build 19043.1110
Display resolution: 3440 x 1440

The Discovery flights are pretty much sandboxed and will have been hand tuned which is just not possible on a global scale. For that we have algorithms and as of yet they still need perfecting. Still I find the flights useful for benchmarking and setting my options, if I can (with no user input) average 24-25fps and not dip below 20 over New York then I am … good to go, flying low along rivers, thru gorges and atop mountains in a TopRudder Solo.

Thank you for the response. That makes sense, and I was thinking along similar lines. I wonder to what extent the discovery flights are ‘sandboxed’. I would assume things like AI traffic & live weather, both of which I turned off during my world map flight scenario, for the best possible comparison. I would also expect the sandbox to break when you move outside of the immediate area where the game drops you, however I noticed the game continued to run smoothly even when I used slew mode to move thousands of miles away. From monitoring the system resource usage, it still looks as though both my CPU & GPU are being under-utilised from world map flights, which strikes me as odd. Perhaps memory speed might be playing a part? I might try a total wipe of the game & reinstall.

There’s a possibility wiping the game might fix (some) crashing problems but I doubt it will do very much for performance. Upgrading to Windows 11 might be a better way to go, at least I’m having no problems. A much quicker download for most of us too and going back to 10 wouldn’t be a problem.

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