You will have to contact Samsung for the upgrade. There may be a better graphics card that Samsung made for that product line. Laptops vary from OEM to OEM and even model to model so you have a very limited amount of upgrades available if any.
Wisecracker said wise words! A8-7200P has 4 core which will help you in multicore gaming whereas hyperthreated 4200u won't cut, and it's only 1.6 GHz processor! Don't get confused with INTEL"S SUPERIOR SINGLE CORE PERFORMANCE in this case, you need more core!
Both iGPU R5 7200p and R5 230 are...
Why not! To get best graphics settings you'll have to tweak/experiment with the options! Saw this video, seems ran good in this system!
https://www.youtube.com/watch?v=44Iy04ZDm7w
Which one should perform better in terms of gaming
1. HP Probook 450 G1 - Core i5 4200m, 8 GB RAM, 2GB DDR3 ATI HD 8750m
or,
2. ASUS X550 - Core i5 4210u, 8 GB RAM, 2GB DDR3 NVdia GT 840m