Dell T3500

so basically i got this dell t3500 4 years ago (xeon w3530 , 8gb ram , 500gb ssd , gtx 750ti) its still running perfectly fine , i was thinking about upgrading it . so according to my budget i can afford rx580 8gb used for like 100$usd ( im from pakistan btw) and upgrading ram sticks to 16gb ram and an 120 gb ssd . The thing im most confused about is upgrading my cpu , given the choices i wana go for xeon x5690 which is supper cheap in pk used goes for about 18$ . Should i go for this setup btw i do gaming on my pc can i have smooth 1080p experience ?