Just recently an addon for OMSI was released that may run OMSI better and more stable: https://steamcommunity.com/sharedfiles/filedetails/?id=2461019058 (there's also a version on webdisk but it's less detailed, missing config and instructions)
Originally we looked at it skeptically but now multiple members have tested it and for most it seems to improve OMSI FPS significantly as strange as it is. It is extremely easy to test it out.
As the author also noted on the download page: On the start of OMSI may have micro sttutering (with similar performance or even worse than without this), due to the shader compilation made by vulkan, but some time later it will stop and the game will run smoothly.
My personal experience:
Loaded up ALU, spawned in Laurenzbach Hauptbanhof. Spawned the Scania Citywide LF12. FPS was around 20-25, which is the same I had without this vulkan converted. I was like okay, nothing changed. Just incase let's drive around a bit, see if there is a difference. Started driving towards the airport and didn't notice anything different, perhaps even worse than before. Then suddenly there was like a stutter and FPS went over 60 (never had this high in Laurenzbach center)......okay, let's drive back to hauptbanhof to see what the difference is, the entire way back FPS was 30+, mostly even aroun 40. Finally stopped at the same place I started, where I had the 20-25, I now is in same area 45+
So to mu surprise, at least with my 3080 eGPU there's a huge difference, over 20+. I'd say it took about 5 minutes for it to kick in.
Volvorider reported 10+ FPS in ALU. NJX reported 20+ boost on the map he tried, Cookie I understand had a bit mixed result
- Up to date GPU drivers
- Newer GPUs that support Vulkan (Nvidia GPUs have to be 9xx series minimum (according to Wiki), minimum confirmed working 10xx series, not sure about AMD)
- Older GPUs
- I think even Windows 7 is not fully compatible with Vulkan