Bad computer perfomance - don't know why

[mikestnaley273]

Computer was working fine about a month ago, although recently, even easy to run games cause me to get low fps. Ran a userbenchmark but still can't find the reason:
https://www.userbenchmark.com/UserRun/13304657

 

[Phazoner]

Check your graphics cards temperatures installing MSi Afterburner + Rivatuner to show them on display when playing. Given that your 970 isn't performing as expected it can be a overheating problem. Or maybe your PSU is dying.

 

[mikestnaley273]

Check your graphics cards temperatures installing MSi Afterburner + Rivatuner to show them on display when playing. Given that your 970 isn't performing as expected it can be a overheating problem. Or maybe your PSU is dying.

I've checked GPU temperatures and they never go above 70C, is there a way I can check whether the PSU is dieing without buying a new one?

 

[Phazoner]

What about CPU temperatures? And which is your CPU? 70ºC is good for any GPU but CPU maximum temps are different.