USB adapters for video are not for gaming - and the performance is less than your current GPU. If you are using it for word documents, email, light web surfing (no video/gaming) - it does a decent job.
The only external GPU's I know of are "kits" that you must modify your current laptop, they are very expensive and they aren't a "neat bundle"....check out this video:
https/www.youtube.com/watch?v=bP_8EYQ-2RA
With a laptop, the best way to get better performance is to replace the laptop. Serious gamers (those who want current games at max FPS) should be using a desktop PC, as it is upgradeable, where the laptop generally isn't....