SLI 980GTX Issue

[Simon 23259]

Hi all, 

I've got an unusual issue with my PC:

When the PC is booted cold, it will be fine with menial tasks until you turn it off, no issue there. 

When the PC is cold and you do anything intensive such as gaming, it will hard crash or hang, sometimes even BSOD approximately 15 minutes after you begin the intensive task. It will always do this without fail.

After being restarted from the crash, it will happily carry out menial or intensive tasks until you turn if off and let it go cold again.

I've run memtest, everything is ok
I've run Intel Burn Test, everything is ok
I've run Furmark from cold, it crashes. 
I've run Furmark post crash and it is okay though my temps are a little higher than I'd like but thats my own laziness in not dusting it out for a while. 

This seems to be a GPU issue but I have had the GPU RMA'd and was told it was fine. (only one sent back because this issue began before I received my 2nd GPU.)

Drivers are always up to date. 

Anything you lovely people can suggest I try? 

System: 

CPU - Core i7 5820k 
GPU - 2x MSI 980 GTX's 
RAM - 16gb DDR4, Corsair Vengance
MOBO - MSI X99 M-Power

[samcool55]

What PSU do you have?

[Jurrunio]

overclock settings? voltage?

[Simon 23259]

@samcool55 Corsair RM850W Gold Rated 

 

@Jurrunio Factory clock until I can sort this issue.