Getting sudden low performance

[Tasmus]

My pc is all of sudden performing very poorly (low fps, slow loading), and sometimes it just restarts. I have made no changes to my setup in a long time and i have been able to play thing like GTA v with 70+ fps and now i can barely get it above 60.
My question Is if its possible that my PSU which is about 7-8 years old can be the problem? or if its just an overall system upgrade im going for?.

My setup:
OS: Windows 7 Pro
Cpu: i5 3570k
Gpu: MSi gtx 780 Lightning
SSD: Samsung 840 EVO 120GB
HDD: Hitachi HDT721010SLA360
Motherboard: ASUS P8Z77-V PRO
Case: Corsair 500r
Psu: NorthQ NQ-4775-650-FLEX 650 Watt

 

[greens]

PSUs do not cause lag, they cause crashes and errors.
70-60FPS is pretty reasonable for the rig and even my GTX 1080 fluctuates more than 10FPS depending on the situation...

I see no problem.

 

[Tasmus]

PSUs do not cause lag, they cause crashes and errors.
70-60FPS is pretty reasonable for the rig and even my GTX 1080 fluctuates more than 10FPS depending on the situation...

I see no problem.

Thanks for the answer. So its not my PSU that is getting to old, but i stil have sudden unstable fps so some games are almost unplayable.

 

[darwins76]

im new here, so please forgive me if im stating the obvious, but have you cleaned the system out with compressed air, mainly heat sinks etc?

 

[Tasmus]

im new here, so please forgive me if im stating the obvious, but have you cleaned the system out with compressed air, mainly heat sinks etc?

im new too, but i have cleaned it recently.

 

[Dovawulf]

Here's a quick list of things to try:

-If you've overclocked anything, reset it to the stock speeds and test out your games again. Do this step first, as it's the easier solution.

-Update GPU drivers.

-Check your CPU temps and see if they're high. If so, remount your CPU heatsink with fresh thermal paste, then test out your games again.

-Check GPU temps, and if they're abnormally high, CAREFULLY replace the thermal paste on the cooler.