should i replace cpu/gpu for better performance in games

[Omnical]

my cpu is fx 8300
my gpu is r9 270 directCU II

 

[Danbuscus25]

getting a new gpu will give you WAY more additional fps than a cpu upgrade. What is your budget?

 

[Omnical]

600 euros and thanks for the reply

 

[Danbuscus25]

do you know what power supply you have?

 

[Omnical]

i have some delta 500w psu i dont know if its good or bad, i could probably change my psu too

 

[Danbuscus25]

PCPartPicker part list / Price breakdown by merchant

Video Card: Sapphire Radeon R9 390X 8GB Tri-X Video Card ($434.98 @ Newegg)
Power Supply: EVGA SuperNOVA NEX 750W 80+ Bronze Certified Semi-Modular ATX Power Supply ($54.99 @ NCIX US)
Total: $489.97
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-07-01 04:02 EDT-0400

I would get that, however i dont know what the prices/availability of those are where you live. a psu thats atleast 650w from corsair, evga, seasonic, antec, or xfx will be fine, plus an R9 390x, or non-x if you cant afford it.