So I’ve made my full map, and i really wanted to add my foliage in at the end to pretty up my scene. I started placing just a few pieces and each one took my FPS down a whole notch, by like the 10th click of foliage i was down to 18FPS and it was in red, also so did my ms up to the 80’s. I tried seeing with the Landscape Mountains demo (made by unreal) to see if it would work fine or not and i placed mass PILES UPON PILES of foliage on the entire map everywhere and my fps never broke 120. I’m assuming this is an issue with how my project is set up but its really messing me up so pls help :D, My computer is brand new and i was so excited to run unreal perfectly but this happened 
( keep in mind it was an almost 2000$ computer), specs: i7 7600 cpu, 1070 8gb vram nvidia gpu, and 16 gb ram ; i think that should be a good enough computer for foliage alone lolol 
thank you for your time, i hope to hear back soon
Is any pc good enough for the foliage tool…Always grinds mine down xD
Yes there is some project settings that could differ, they may have set the scalability settings carefully to fine-tune the foliage, but I wouldn’t expect as much of a difference as you describe. Is there any chance your spawning something too much by accident. Some twig or rock that accidently got a density of 100000?
You could do the console command ‘stat unit’ to see where the lag is, its likely the gpu, so you can do a ‘profile gpu’. Also try placing the default cubes as your foliage mesh instead of a nice plant, see how framerate is then, if its fine your mesh might have problems, and also check your instance numbers that they haven’t grown to crazy numbers by accident.
Thanks for responding so swiftly :DDD i really appreciate it man, and no i just figured out that on every project its the kite demo grass mesh that’s messing me up bad, the density could be tiny and it’ll still drop the FPS a boat load, also may i ask where to look in the stat unit, also what is an instance number? Sorry, I’m fairly new and and trying to learn so thank you for all your help
So i just found a temporary fix, i figured instead of painting masssss portions i decided why don’t i just drag and drop from the content browser and resize the grass to be way larger and just rotate them and put the foliage in that way; for performance its complete amazing, it doesnt look too terrible and its quite simple,. the cons of this r pretty bad, first: it looks a little stretched out so i wont get the sexy unreal feel with graphics, its 100% less efficient than painting with the foliage tool, and the shadows become a little awkward. I just wanted to point out this method works but it will suck nuts to have to do this for a mass open world map
You could try using the landscape grass tool and procedural foliage volume for big amounts of foliage.Also,another thing you could try is to disable the shadow on grass foliage.