That computer ... yea, it would be very sluggish. With 4Gb RAM you're barely able to operate, and I'd bet the rest of your system is similarly ... lagging.
A complete listing of OS/CPU/RAM/GPU/vRAM, and also disc layouts .. 1, 2, 3 or more? Internal/external? Such things could help us tell you what to expect. Also, there a LOT of info on the Hardware Forum found through the side-panels to the right of the Overview Page.
Neil