High level assets not loading

is this my computer, whenever I open high end asserts like the free twinblast guy unreal engine 4 would freeze up until I force quit it, guys help, really want to make games with ue4.

my iMac 5k (2017) specs

cpu= 3.4 GHz Intel Core i5
memory= 8 GB 2400 MHz DDR4
gpu= Radeon Pro 570 4096 MB

thanks!