Yea, those specs are not gonna cut it for modding if you want to be quick about it sadly. I just built a new rig for Game Design in UE4 & Character modeling in zBrush with the following specs and I still have to be considerate of my memory usage;
i7 3.8ghz 3770, 16gb (32 later today when I upgrade further and then I shouldn’t need to worry ever with modding Ark) of DDR3 ram, and a Radeon R9 290 (soon to be 2x).