looking for CAD laptop for under $3500

hi. my friend is looking for a laptop for college for engineering and is looking for a laptop to run autoCAD and also do some gaming. he asked me for advise but the problem is i don't know that much about CAD. all i could figure was that it needed a decent GPU because of the 3d modeling, but does it implement vRAM at all? i don' know so i'm asking for help.

he needs:
dual core processor
17'' screen
battery life of at least an 1.5 hours.
discrete graphics card (he will be running a second monitor)
under or around $3500

this will be his only computer.
thanks in advance.