Rate my rig

I had my friend help me build this rig, as well as offer to help pick out basically all of the parts. I still really don't have a grasp on things such as compatibility, bottle-necking, price-to-performance, and things of that nature. So basically what I'm asking for is opinions on this rig...

Between a RX 550 2GB and a R7 250x 2GB DDR5 Crossfire, which will give a better performance. No need to consider the prices of the cards.Just need the performance comparison also no need to sweat about the details or problems of Crossfire.

sorry, not sure how to delete my own threads