Generic PSU + Used GPU = PC reboot in SPECIFIC games

[NoobUserLOL]

Need help with this extremely problematic situation. I will start explaining from the beginning:

My computer has the following hardware and i was using this specific config since i built it 6 months ago

Gigabyte-z270 gaming K3
Corsair LPX 2400mhz
Core I5-7600k
GTX 650 (....i know )
CiT ATV 550W 80+ Bronze PSU


All these parts were gifted to me by a relative and the computer worked fine for 6 months, i already had that old GTX 650 i mentioned and bought the other necessary components (1TB HDD, Case and 5 120MM Fans and a decent heatsink)

Just recently my cousin gave me his old GTX 970 G1 Gaming (for $120... out of pity) and for the first 3 days after installing it the computer worked flawlessly however just today ive started getting reboots in certain games, no BSOD, no CTD just a plain reboot which occurs randomly with random times ingame, computer works fine after reboot

Now heres the weird part the only games causing reboots are:
Firewatch
Fallout NV with ENB and 2k Textures.

ive isolated the problem from my RAM and GPU thru memtest and unigine superposition. im using MSI afterburner to monitor my usage and temps, i have vsync on in all my games so 60FPS is the max, i also tried other games like Witcher 3 and AC4 Black Flag maxed all of which push my CPU and GPU to near more than 80% usage but the comp refuses to reboot in them. Max CPU temp is 60 degree Celsius and 65 for the GPU.

now i know that i have a shitty generic PSU from a local brand only found in the UK, i guess it is worth noting that the PSU started giving coil whine 1 month early also both the pcie power cables are daisychained.


I know most of you are gonna recommend a PSU change but those which fall into my affordability range are Corsair Cx and Vs series, no other brand is available where i live and as far as reviews go people dont have much good to say about them and prefer other brands on the same pricepoint like evga

No reboots have happened yet because of browsing or general usage. Its funny how extremely demanding titles and torture tests arent causing a reboot but the above mentioned ones which use about 50% of both CPU and GPU @ 60 fps are... nevertheless i am quite concerned about the problem and i hope someone is able to deduce the origin of this problem and which component is to blame

 

[jankerson]

If on a budget the NEW Corsair CX550M aren't THAT BAD.

 

[Dark Lord of Tech]

Get a Corsair CX or CXM 550W , the Black and White models and that should help.

The new CX non Modular is actually better quality than the Modular version.

 

[NoobUserLOL]

Oh i see that the CXM 550W costs $60 on amazon, hopefully ill be able to get one for about $80 where I live, its a third world country after all ;_; thx for the suggestion guys, seems that ill be stuck with a 720p monitor with a DVI to VGA adapter for a looong time

Anywaaayyy its quite sad that 99% of the time the PSU is always the culprit in problems like these, ive searched a lot and have also come close to a problem very similar to mine.... the OP always ends of changing the PSU and -_-

However i still wonder, could this be some kind of windows related failsafe thingy that instead of giving me a CTD the computer just reboots? I dont think this is a bad driver install but does that indicate some sort of incompatibility between the Graphic card and motherboard? I still have not updated the Mobo BIOS becasuse blackouts are so random and frequent

 

[Dark Lord of Tech]

Hard to diagnose sometimes if the power supply is not of good quality.