Why the mention of an external drive? An external drive is used to transport large amounts data between different machines/locations and as a (moderately reliable) backup. Not to run programs from. Use an internal hard disk for that.
To make my question more precise, is there any way I could play for instance a game like Sims 3 in a HP Envy 14 Spectre? Would and hp external drive be good enough to play it without it getting too slow? Thank you in advance