dell vostro 2702 sff

HI everyone, 

i am trying to upgrade a old dell vostro 270s sff, currently used by my kids.

on the original mother board i add 16gb ram ddr3 i update the processor with a i7 3770 3,4ghz

and a Gc geforce gt 1030 2gb and a regular ssd hhd. It works fine for general task as word youtube, or minecraft.

Would like to ask for some help: what else can i improve on this small pc, to make it better, i saw that still struggles with simple games like roblox and a youtube open at same time.

Maybe change the mother board to be able to have a different grafic card, (what the best mother board i can put in this pc?) i guess would need a more powerfull power supply coz i think currently works on 220watt.

thank a lot guys.