Question Is my RX 480 dying ? If not whats going on ?

[Hydroshot]

Ive been having Issues with performance in demanding games that has been getting worst and worst over time and i have no idea whats going on, about 2 months ago i was able to Play GTA 5, DayZ, Forza H4 and many other games 60+ fps just fine but recently my performance has been decreasing dramatically im now only getting Constant stuttering in these games and i feel like my GPU might be on its way to its grave. Ive only had the RX 480 for about 2 years and ive NEVER overclocked it and the temps are perfectly normal. I also just recently upgraded to a Ryzen 1600x .. I feel like the issue could be traced down to the power supply but im doubtful of that since ive only had it for 3 years and its been awesome, its an ANTEC HGC 620w and its pretty high end.

 

[Vineet is genius]

Was the performance goood Before upgrading to ryzen 1600x
Or it got worse after upgrading