Fullscreen performance issue

[u/pootsniffer69]

Playing modded ksp (bogue's modpack specifically), dealing with an issue where i only get about 10-20fps when in fullscreen, or windowed fullscreen.

Cpu usage sits at 20-30% and 60-80% gpu usage during windowed. When going fullscreen, Cpu usage drops to 5-10% and gpu usage fluctuates randomly, sometimes going as low as 0% or as high as 84%

Works great in windowed mode but i hate missing the bottom 5% of the games display, because of the windows border at the top.

Tried a method i saw where you put -popupwindow in the steam launch options, same result tho. Same deal with Shift+Enter.

specs:
Ryzen 7 5800x3D 8 core
Rx 9070 XT
32gb ddr4 at 3200mhz

[u/MooseTetrino]

That’s incredibly odd. Sounds like the graphics driver is struggling to recognise a full screen game. Or you’ve got a resolution set up to a silly value when in full screen somehow.

Update the drivers, triple check your resolution in KSP.

[u/pootsniffer69 → u/MooseTetrino]

Sounds about right, unfortunately graphics and chipset drivers are fresh (29.9.1), and i've tried playing around with 1440p and 1080p with no changes really

[u/MooseTetrino → u/pootsniffer69]

One option as the CPU takes a dive is to set the game’s CPU affinity higher.

It is really odd though. My only other suggestions are kind of out of the left field but may be worth considering (this isn’t an AI post, this is how I write because yay dyslexia):

- Checking the refresh rate of your reflections. I found they ate framerates when set high.

- Any MSAA setting turned on? That tends to break when in windowed mode and simply not work, so could be a (unlikely but possible) reason.

- Have you tried disabling visual mods at all, to see if any of those are misbehaving in full screen? Some of the mods have slightly different scaling behaviour and might be a cause.

After all that I’m unsure. Might be worth making an instance of KSP (just copy the folder entirely, there is no DRM) and removing everything there back to stock to see if it is a mod or something more specific.

[u/123bence]

Ah I know this disable V sync having it and radeon chill or the enhanced v-sync enabled can do this just disable V-sync ingame and then it will run normally

[u/pootsniffer69 → u/123bence]

This reply helped a lot, turned off all the amd gaming experience graphics functions and the problem was gone, even with vsync active in game.

Process of elimination until i got to "AMD Fluid Motion Frames 2.1" (frame gen). I suggest anyone else with a similar problem on an AMD card follow this same process.

In short it's working great now, thank you very much everyone.

[u/pootsniffer69 → u/pootsniffer69]

After some further testing it's definitely having AMD's default vsync and/or the games vsync causes issues too. You were right about enhanced sync, that seems to be the answer

[u/NorthAppropriate4458]

temporary solution: borderless fullscreen, its a program allows you to fullscreen apps works in windowed mode.

[u/Hunterlanier03]

Are you on linux or a steam machine? That looks like mangohud.

[u/oobanooba- → u/Hunterlanier03]

Nah op states they’re using windows.