I am currently using UE4 version 4.9.2 and noticing at times the memory usage is off the charts. The machines I am running on have a large amount of ram ( 128gb ) and it seems unreal is happy to eat up half of that or even more. On other machines with only 16gb it often takes up over 13gb of ram.
Is there a way to limit ram usage?
Is there a known leak in 4.9.2 that would cause 62GB of ram for a scene with ~1400 actors?
Any insight would be helpful.
I have the same problem with 4.10. I am running it on a GTX970, intel 4.0ghz processor, with 16gb of RAM and just randomly during my session, the editor will use up to 15gb of RAM.
same here, I have only 8gb RAM and after a while the editor has eaten as much as it can from the remaining available RAM. using v4.10.1
when I start the editor and load my level it uses only ~1gb RAM
EDIT: I’m not even adding anything to the scene, I’m only editing blueprints and testing in PIE mode.
EDIT2: seems like everytime I open a new asset, different blueprint or staticmesh to view it eats a bit of RAM and never releases that used RAM unless I quit UE4.
So is there are way to limit the RAM usage on the editor so it would at least leave me 2gb RAM free? or an option to release the RAM it uses per opened asset in asset viewer by closing it?
I don’t believe there is. I have the same problems though. Sometimes its fine other times I start running really sluggish and look at the taskbar and it’s using 15 gigs of ram.
Need more RAM, milord! 
Same problem here. I have an i7 950, GTX 970, and 24 GB RAM. Using version 4.10.4. It depends on what I have open, but often I encounter a hard freeze due to no free memory. Without Max/Photoshop open, UE4 will consume ~19GB RAM at random times. I can leave it minimized after loading a level and it will be using around 2 gigs RAM, and at some point it jumps to 99% memory usage.
I hope they figure this out soon! It does make me CRTL-S after every change now, though.
I guess this has been fixed in the latest pathces now. I haven’t had a memory usage problem lately, at least not on v4.13.2
Now the RAM keeps in respectable amount based on level/project size
I have got 4GB RAM and it needs 2-3,5 GB 
yes there is … i just forgot how to do it …
there is a file in unreal systems folders that you can modify with notepad
i think it’s an ini file
it has one thing in it relating to ram/memory mem something or ram something or memram something like that
you can specify in the file how many gigabytes unreal can use preventing unreal from choking your machine but it probably wouldn’t help unreals performance that much.
like it won’t lag as much but because its working with fewer resources you can expect some reduction in that specific programs performance. (it would still be better since your “computer” wouldn’t be choking and lagging)
i forgot how to do it exactly, I did it once though on my 7 year old laptop sporting 8gb ram and a 5xxx series radeon. i accidentally found something on the internet about doing this and ive been searching for the posting ever since :S
[SystemSettings]
r.MermoryLimiter=3013
-lowmemory=3013
r.Mermory.Limiter=3013
MermoryLimiter=3013
limitador
Is it supposed to say MermoryLimiter? Or is this a typo?
It seems like this option goes into your projects /Config/DefaultEngine.ini
But I’m still a bit unclear on what it actually does and how it works. There seem to be no documentation about this option at all.