Icelator

Hi all,I'm looking for buy one of the chip(exp gdc or pe4c) for my laptop dell insp. 7520. (8gb ram,core i5 3210m 2.5-3.1ghz,igpu and amd dedicated).I would to use a basic gtx 970.. I read all the advice and my question is what type of egpu support give me overall the best performance? How much gpu potential is approximately lost comparet to desktop use? My cpu is powerful enough for AAA game? Thanks