Thank you for your respond! that’s weird because i had a couple rect lights before and i had a successful light build with lgpu, however i had a long skylight radiousity before mapping process on swarm status, it was like 6000 seconds and cpu was on full load without any gpu utilization after a while while on the mapping stage gpu took over untill the end with 100 percent utilization alongside the cpu!! when i opened the project they were looking fine! so i suppose that baked only the direc light of the rect light? and also sometimes my light bake with lgpu takes soo much time and it barely even progresses and eventually i just canceled the building, is there something that i’m missing? i’m baking with production and my base lightmass settings are (primaryGISamples: 128 secondaryGISamples:64) world settings: indirect and skylight bounces are also 10 and sometimes i tend to decrease volumetric lightmap detail cell size to something around (30-50) which i couldn’t ever build with that volumetric size it always just gets extremely slow and after a while i just give up and cancel the build! and when that happens my graphics card also gets too cold but with something like 80-100 utilization, vram around 7 to 7.9 gigs (i have a rtx 2080 with 8 gigs of vram). am i really missing on some settings or anything like that? or that my gpu just can’t handle it? also as i said in my first post if there is a workaround to start my build with a command or something so i can save some vram and etc… i would appreciate a lot if you could tell me how to do it so i can follow along.