Hey guys!
 
Hope everyone is doing well. I'll try to keep this as short as I can. For about the past 12 months I've had an issue with my PC to where it will just randomly (99% of the time during games) restart. I've swapped out hardware in hopes to narrow down the failure with no such luck. Things i've replaced, SSD (fresh install of 10), PSU, RAM. I even cleaned out my case, re applied thermal paste and bought new fans along with a fan controller with thermometer probes so I could more closely monitor temps (They arent a Issue). The trigger seems to be specific games, although the games have changed around over time. Certain games seem to cause it more often, with other seemingly never causing it (I can play tarkov no problem but CS:GO or EXANIMA will cause it to restart for example.) I've started to think its maybe GPU. I got Furmark and ran the benchmark for a few hours hoping to cause a restart with no such luck. I've also got some other benchmark's that seem to run okay with the exception of a older one that caused a reboot. I have a EVGA GTX 1070 SC card and it's out of warranty, is my best bet to just buy a new card and see if that fix's it? Could it be something like my case, or motherboard or CPU? What would you guys recommend for trying to diagnose the issue next? I am running a over clock, but it does it even with the stock clocks, my OC is quite stable. 

Thanks for any help at all.
 
Bios is latest version
PC Specs:
Intel i7 4770k @ 4.0
MSI z97 PC Mate Motherboard
Crucial MX500 1tb SSD
Corsair Vengeance DDR3 1333 @1600MhZ 16gb
Corsair HX750W
EVGA GTX 1070 SC 
GPU Temps while gaming are generally around 58-60c
CPU temps while gaming are generally around 43-48c
 
 

A faulty graphics card would do it, so would RAM..Furmark would definately load it up good, power/temp-wise.

Set the RAM to run at it's rated frequency/timing/voltage and at a 2T/2N or 3T/3N CMD Rate in the BIOS..Then try it..You can run Memtest to check it for errors/failing..Windows has Windows Memory Diagnostic built in, type Windows Memory Diagnostic in the search box, or find it in Control Panel\Administrative Tools.

Try your graphics card in another PC and see if it acts up..Try another graphics card in your PC..Take your graphics card out and use the 4770K Processor Graphics and see if it still crashes.

Cool GTX
reboots under load ... PSU & its cables would be my first thought ... I know you changed it but
 
Yeah i took everything out and reseated and cleaned everything a few months back everything looks fine. different psu cables with the new psu.
 
Have a UPS ? is it near Max load ?
 
No UPS, but i do use a power strip (I've tried 2 different ones). One thing to mention is my apartment is from like the 20's and it doesn't have the 3 prong outlets. Could that be the issue? I am using one of those converters. Just odd that it would all of a sudden crop up after living here for 4 years. 
 
Test your RAM & CPU
 
The ram is pretty new, only a few months old, I RMA'ed the old sticks because one was bad and they sent me what i assume is new ones. But i have not run memtest on the new ram so thats something to try. I guess i ruled the out being so /new/
 
Remove your OC settings all back to stock ... does it still reboot ?
 
Yeah i've tried this with no luck. 
 
What OC software are you using for the GPU ?
EVGA Precision, I've tried removing the factory OC, and the only stuff i really mess with is the fan profiles and i turn on kboost. *(ive tried truning it off)
 
Which Nvidia drivers have you tested ?
 
This issue has occured over multiple versions of drivers. Cant really pin-point one, I use the geforce expereince. Although i've done a few DDU re installs just to see. 
 
Any information on the Game sites about this issue your seeing ?
 
Not really because it happens on most games i play actually, It's really restricted what i can /reliably/ play and quite frustrating. 
 
Have you Replace your SATA cables ? are they a tight fit or have the locking metal tab ?
They are a tight fit i believe, they do have the little metal locking tabs but they are pretty old, something for me to try. 

 
Some other folks mentioned memtest which i did run on my old sticks of ram, and one was bad and thus i got the new ram so i've sorta ruled that out. I guess that is something for me to try. I'm gonna work on this stuff prob later tonight and will report back if any memtest errors. also gonna see about getting some new sata cables maybe. 
 
Someone mentioned the restart button and I thought of that to and disconnected the header on the mobo a few months back, and it still happens. I thought about maybe trying the power button but it would be a pain to turn the PC on without it. 
 
 
What's good software to test out the VRM on the CPU? 

Also one other thought.  I know you thought your OC was stable, but especially if you've been running it for a very long time, and the fact that is a 5 year old CPU it's probably had some degredation so you might need to bump various CPU related voltages a notch.  I had an old i7-860 that was stable for a couple years at one setting then eventually needed the next step up in vcore to stay stable.  If there's been enough degredation then I could see the related instability even happening at stock settings since now the predefined vcore in the chip for stock is no longer enough to keep it stable at stock.

So I dug up a old evga gtx 285 and im gonna run that for a while see if i can get it to happen again. 

I guess we shall see, I got the gtx 285 in and played CS:GO for a couple hours last night no issue, which is a game that causes the restart quite often. 

99.99% sure it's GPU. Been running no issues now with the GTX 285 for a few days. My 1070 out of warranty, I literally refuse to buy a GPU with the market how it is right now, so I shall wait few more quarters. Id be looking at like 500 to get a decent upgrade from the card i have no i believe.  Thanks for all the tips and everything.