Hi,
There is a discussion found bellow in X4 Foundation forums, where at GPU bound scenario both RDNA1 and RDNA2 GPUs do not perform properly with the Vulkan game engine.
https://forum.egosoft.com/viewtopic.php?f=146&t=441417
One user has 1080Ti, 6900XT and 3080Ti and run tests at 2560x1440 and was perplexed why the 6900XT is so slow.
Another user joined in with a 6800 and myself with a 5700XT AE.
GTX1080Ti shows 60% higher fps compared to watercooled and overclocked 5700XT AE, and 10% faster than the 6800.
3080Ti is 45% faster than the 6900XT which is barely 25% faster than the 1080Ti.
All GPU scores are at 100% GPU load and max speeds.
Is there a driver issue? Is this a game engine issue?
1080ti (evga sc2) = 120 fps - 125 fps
1080Ti (strix gaming oc) = 125 fps
3080ti (gigabyte aorus master) = 232 fps - 238 fps
6900 xt (amd reference) = 160 fps
6800 = 115-135 fps
5700XT = 70-80 fps
6700XT = 80-95fps (update)
Thank you.
Update
Another user tested the set settings with a Radeon VII
72-108 FPS, ~195 watts GPU usage, ~1750MHz Core, 1200MHz vRAM - Increased vRAM speed and undervolted GPU.
75-113, ~280 watts GPU usage, ~1900MHz Core, 1200MHz vRAM - Heavy overclock with +20% power limit.
68-103, ~190 watts GPU usage, ~1750MHz Core, 1000MHz vRAM - Mostly stock settings except for an undervolted GPU.
The low end of the FPS is at the same scene with all the AMD & NV cards.