Concentrate on memory first. When you go to do a build… You will be happy to see that you have plenty of memory. Also when you are not using the UE4 Launcher? Close it, it sits there silently consuming resources, just watch it in the task manager and you will see what i’m saying.
If you can do it, but it’s going to take some changes, New Motherboard, that supports DDR4 memory, 16GB of memory, and a new processor, something like the AMD 4Ghz 8 Core processor.
Hope this helps.