Built a new rig a few months ago had to send away to the US to get the classified as I wanted to try three way sli and needed a board with the plx chip.

Decided that I wanted better 4k graphics so invested in a 2x 1080 ti setup.

Put in the cards and upgraded the psu to a 1000w. Ran stress tests and benchmarks without issues. But games on high resolution seam to freeze without warning nor does it appear to be under load at the time. Have to hard reboot to get it back to life.

Thinks I have done :
Replaced the ram completely and tested it nil issues.
Changed back to a 2x 980 gtx configuration
Tried another psu
Tried a fresh install of windows 10 on another hdd
Ran the games off a different drive
Unplug all hdd except os and games drive
Reset bios and updated to 2.0
Rma my two 1080ti cards waiting on the replacements
Ran memtest ran prim95 ran 3d mark ran gpuz log (log shows normal operation before crash freezing)

I'm out of ideas.
Just to be safe have purchased a 1200w psu coz I could and getting two new 1080tis to replace the old ones.

Is my mobo stuffed?

Specs :
EVGA Z97 classified
I7 4790k
Usually 2x galax gtx 1080 ti in sli with EVGA hb Bridge
Currently 2x gigabyte gtx 980 in sli
Samsung 250gb ssd
4 mechanical drives
4x 8gb g.skill 1333 ripjaws ram
Cooler Master 1000w moduler psu

I'm out of ideas before I bin this mobo and build again. Any help would be greatly appreciated.

Yeah though the bridge might be the issue so also tried the old sli cables same issue. Sorry was one of my process of elimination tests.

Yeah every slot.

Guess it's time to swap to a new board.

Doubt it's a voltage issue if you're running everything at stock.

Just a thought I us a program called controller companion that I got from steam so I can use the Xbox 360 controller. Now when it disable sli and or turn it back on I must exit the program before it can do it. Now I have disabled it in start up. I still get the crashes but could it be a conflict possibly?

So spent all night rewiring the system. Reinstalled driver after uninstalled with ddu. Ran memtest for 10 hours then ran prime95 and kombuster together and the thing didn't skip a beat. Seams it's just games that are causing the freezes.

Has anyone at all ever experienced anything like this?

Does anyone know of a program I can use that will tell me what the last state was before a lock up? Windows logs shows nothing other than power was cut unexpectedly.