EVGA 1300 G2.
 
Also connected both cards into their own 1600 P2 power supply to see if that was the issue. It was not. Power does not seem to be the problem. Power was mentioned all over the internet. It was one of the first things I tried. Has no effect at all. 

Oh the same guy.. was wondering..

Why the new thread?

I take it you have not bothered to reinstall windows yet?

Cause that's the next step.. then replacing the mb.

They never seem to get above 65 actually. And only in SLI. Usually crash at about 63 degrees sometimes 65. But from what I can find, that Temp is not that far out of where stress tests get. 
 
Here is HWiNFO64 test results from running in SLI till it crashed in Fire Strike
https://drive.google.com/open?id=1kw1K9OUbsYU1FzVyWJBWfCUv9-b6jC8L
 
 
Here are three Heaven SLI runs till it froze the PC. Same place every time.
https://drive.google.com/open?id=1RFfIuHUgQt46qKo1o4PbajXsxCDgs-Il
 
Safety feature build into card is all that I have not tried to see by replacing Air cooling back on the card and plugging in the fans then running test again. and I really don't want to have to go through all that. 

Re did windows. New MB coming tomorrow to test. 
 
New thread because I'm more interested in knowing if the cards have a safety feature for temps that can shut them down. Cant find info on this being a feature and/or fans need plugged in to circumvent the feature as the EVGA water blocks have this plug on their cards where EK does not. 

I dont see why. Ek would know this when making a block for the card.. other people would also be experiencing the same.

If it was some safety measure one would think it would trigger at a much higher temp like 80-90c.

What rads are you using for these 2 cards?

I'm thinking the contact isint great maybe.. unless your running a single 360 rad?

So all this time I had no idea you were water cooling these cards in the prior thread.. wondering if there was a problem with the block install on one of the cards.. something not right possibly grounding/touching on something thats causing this sli issue.

Yeah.. removing them would be a huge issue. Your going to doing it swaping out the mother board soon I bet.

Trying a new motherboard tomorrow. But i feel there is either a bottle neck somewhere or auto power shut off. Everything else has been tested for the most part. I see stuttering right at the beginning of the benchmark in SLI but not on a single card run. Also see the stuttering right before the crash in most cases. 
 
Not a small water cool set up. See pic: https://drive.google.com/open?id=1Fsyr2vvkhuMD43CX7kUTncDOJXgfUyKM
 

Time to try a new bridge.

Combining this thread with your other one.