[gnufied]

> For developing with UE4, we recommend a desktop PC with Windows 7 64-bit or a Mac with Mac OS X 10.9.2 or later, 8 GB RAM and a quad-core Intel or AMD processor, and a DX11 compatible video card. UE4 will run on desktops and laptops below these recommendations, but performance may be limited.

[ctdonath]

"Recommend". If you're trying to develop as close to "free" as possible, "performance may be limited."

(I'm often puzzled that when I suggest a nigh-unto-free solution to a problem, someone usually complains some form of "but that's not optimal!" Of course it's not optimal if you're not willing to put substantial resources into it. Just because the solution isn't perfect doesn't mean there isn't one; do what you can with what you've got, and you'll make progress toward perfection.)

[esrauch]

I think the point is that it is going to be worse than just laggy UI, it's going to be very painful if you try to use that computer for developing using UE4.

Which isn't to discourage people, there is a lot you can do with that kind of mid tier machine, but you are probably much better off trying to something else than UE4.