PSU or GPU causing stuttering

[Jakrispy]

I've been experiencing awful stuttering/lag since building my pc back in august. The most common thing that will happen is that I'll play 5 minutes into a game before it just starts dropping frames and stuttering like crazy, but whats funny is that I can play certain games like Portal 2 and Titanfall just perfectly, but games like GTA San Andreas and Minecraft are unplayable. I think I've narrowed it down to being my PSU or my 290x which I bought used off of ebay. I get fairly average cpu benchmark scores, and gpu benchmark scores as well, but as soon as a start playing an actual game, its just a stuttering laggy mess. 

 

Specs: 

Reference R9 290x (Watercooled with NZXT G10 and Corsair H55) 

Amd FX 8350 (4.6ghz) 

Corsair H100i 

Asrock Fatal1ty 990FX Killer 

Corsair CX750M 

16gb (2x8) Corsair Vengeance LP 

120gb Kingston SSD 

1TB WD Blue 

[ELSknutson]

have you tried turning down your overclock?

[Laputacake]

Did you check to make sure the graphics card wasn't mined on and what are the temps?

[Jakrispy]

have you tried turning down your overclock?

I've had this issue before I overclocked my 8350

 

Did you check to make sure the graphics card wasn't mined on and what are the temps?

 

I never checked if my graphics card was used to mine. I get about 60C in games most of the time 

[ELSknutson]

Mine Craft is more of a CPU based game so it makes me wonder if theirs not an issue with your CPU. Are you able to try your graphics card in another system?

[Samsterstorm]

I have a AMD and they just do not work with minecraft i cannot get rid of my stutter and just look at my specs! I have read that it needs a shit ton of CPU horsepower because it autosaves every 2 seconds so the frames drop and AMD CPU's just cannot handle it even overclocked! For some reason NIVIDIA and INTEL work better!

[Jakrispy]

Mine Craft is more of a CPU based game so it makes me wonder if theirs not an issue with your CPU. Are you able to try your graphics card in another system?

I'm not, the other system I have doesnt have GPU power connectors