Absent.Dogma ,
you may want to shrink the distance of the trees before they become billboards. Not a hundred percent on how to do it in unreal, I spend most of my time in unity and there it is a slider attached to the terrain... i did find something from 2016 and they suggest
- Render 3D Imposter Sprites
- Render a Normalized Depth Map
main thing when you have that many trees you need to get creative because they have a lot of parts to them and if the player has to render 50 trees in a 10 ft radius.
I would also try whatever the unreal version of mixed lighting is, because baking your static objects(things that dont move, ie. buildings) and only lighting the dynamic (things that move) ones will really help with performance (just doing this will help tremendously).
if you haven't already GPU instance your repeated textures (again whatever the unreal method is).
your fires likely use particles, try not to have too many rendering at once, you will likely be able to find a happy middle ground between too few and too many particles generated (a dollar in pennies is harder to count than a dollar in quarters). the next step can help here too.
Bake Occlusion, it will unload anything within the desired radius, so if you are in a forest you don't need to render the whole map, just the 20ft radius the player can see. if that isn't an option set up triggers around the map to load and unload objects as people pass them. this may be resolved by completing my first suggestion.
This is what I've picked up so far while I have been attempting to make quest compatible content and there are severe hardware limitations there (I really hate mobile OS), but the same principals should apply towards those budget gaming rigs.
I hope i didn't bore you with things you already knew, games runs just fine on my end, usually dont drop below 80fps using an rx580. I also just like to be thorough, so im sorry if i made my descriptions too simple. <3 u
saigyjouji your CPU could be bottle necking your GPU(if your CPU is as modern as your card your prolly fine but if you still have ddr3 ram or a dual core processor you are definitely being bottle necked and should upgrade your chipset). I have found that my Nvidia cards run better with intel and AMD with AMD, most times i run into issues when i pop an Nvidia card into an amd chipset(usually just random frame drops nothing consistant)but AMD cards seem to work fine in an intel setup. Have you used the card for mining or rendering? if so it could just be worn. Check your BIOS and firmware are up to date, update Nvidia.