This issue has been happening for 4+ months, since the first build of the computer but has gotten worse. It powers off and restarts itself as if the plug got pulled from the wall and restarts immediately(No BSOD). I have tried many things searching for the fix on many forums narrowing it down to possible faulty PSU but wanted to see what you guys think.
 
System specs are
 
CPU:             i7-6800k (Never overclocked, trying to sort out issue first)
CPU Cooler:   Swifttech H320 X2 AIO
RAM:            4x8gb Crucial ddr4 3000mhz
GPU:             2x GTX 1080 Zotac AMP EXTREME (never overclocked)
Motherboard: Asus Rampage V Extreme Motherboard
SSD:             256GB samsung 850 pro With Windows 10 x64 installed
M.2 SSD:       512GB Samsung 950 pro with steam games installed
HDD:             1TB HDD with nothing on it.
PSU:             1000w EVGA supernova t2
 
What causes the issue to happen is playing video games. Any game will cause the crash regardless of GPU demand such as- Age of empires 2 HD edition/League of legends or Witcher 3/Total war: Attila. There is no rhyme or reason, it might not occur through 8 hours of play or it could happen within 30 min. Sli Disabled or Enabled. 
 
Temps: Using Zotac's Firestorm GPU program the GPU temps stay less than 70c.
Using Core Temp CPU temps stay less than 60c
Voltages: In BIOS all rail voltages are close to the mark.
Memtest x86 ran overnight with a pass.
 
Thanks for reading and I am willing to try anything you guys shoot out to try to fix this problem. I am probably missing a few things i've tried to fix this because I've tried a lot of stuff.
 

I'll try it out. It could take me a while to find out because it might crash once a day, but ill be sure to post if it finds anything when i do get a crash. Thanks.

It had no Minidump files after I hit analyze the first time so i manually initiated a crash and the manual shutdown showed up on restart. I'm thinking i've gotta wait for another crash unless these crashes don't show anything on the shutdown (if they can?).

So assuming faulty PSU there would be no Minidump on a shutdown? Thats really good you ruled out drivers, I will still keep this program and run it after every shutdown just in case. Thanks. If you have any other idea's i'd love to hear em.

Okay. I think I'm gonna start the RMA process, if anything does come up after a shut down i'll be sure to post again.

Computer shut down while I was un-installing malwarebytes. No crash dump analysis showed up.. This was with only a single GPU inside the computer- testing stuff out. It rarely shuts down unless I am playing a video game either which is weird. Still hunting for the reason if anyone has a second thought about it.

Yeah I tried that actually, both video cards act the same. Thanks for the thought though.

Devone
I reset cmos and the computer smartened up... hasn't shut down in 2 days now since the cmos reset which is a huge improvement. Hopefully it's fixed now.

Doing a reset usually fixes many problems. Hoping it stays good.