How does unreal engine handle memory?

Hi! im doing a scene with 12 buildings. im using a lenovo y510p i7 4700MQ @2.4ghz turbo boost @ 3.4ghz/ 8GB Ram/ dual gt755m sli mode. In the image below are six of them. Later, as i finish detailing, i will copy those and rotate them and place them on the right side which makes for a total of 12 buildings. as you can see i already have 4000 actors in the level and whenever i build my lighting i watch my resources and all that remains is about 1gb of ram. so my question is: how does unreal utilize memory? if i actually do as i plan (not to mention that by the end, as i finish detailing it will grow up to 10k actors plus a number of foliage that i will insert from the kite demo) will it still use the same memory as if it is only using what is available? or will it ask for more ram and crash if i dont give it to her? thanks! i really want to understand more so i can properly use the engine. thank you very much!

When building lighting, a lot of RAM is expected to be used. Are you using a Lighting Importance Volume to reduce the area of Lighting to be rendered? You should use them for building lighting.

But with that said, 8GB of RAM really isn’t a lot at all when it comes to building lighting. Baking images/video in just about any rendering application will use as much RAM as it can.

Also how many foliage instances do you plan on using in your scene?

About 50 trees. Nd yes i have lightmass importance. I think its visible in my image (yellow box). I just detailed the first building and i pressed build lighting. After it exported lighting data 100%, unreal froze. I dont know if it will still recover. What should i do to be able to finish this huge scene? Im really despertae now what should i do?

Ive read some threads about lpv and not using lightmass? What exactly is that? Can you please explain to me i didnt really get what they were talking about on that thread im a newbie. Thank you very much louie :cry:

Okay. it froze because i set all my lightmap resolutions to 8k. i brought everything down to 4 except for the floor (still 8k). froze. made everything 4px. then it built lighting so fast. i think ill just increase lightmaps little by little. thanks!