I have to the following strange problem with this modpack. With a fresh installation of 3.5 with a fresh new world on a server (linux x86_64 - Core i7 - 32GiB RAM) or on a client (windows x86_64 - Ryzen 7 1700x - 32 GiB RAM) one CPU core is always at 100% (even with 12GiB of RAM assigned - so GC shouldn't be that much under pressure). Anyone else having the same issue? Or is this behaviour considered normal for this modpack= (I don't know of any other modpack having the same behaviour).
EDIT: After some investigation we found out it has something to do with galacticraft background world mapping - after a while the cpu usage went down to normal levels.