PC crashes/restarts while gaming at 144Hz

[randomgeek]

Recently I brought the Acer Predator XB271HUA (bmiprz). I've found that playing at 2560x1440 at 144Hz makes my computer restart randomly. Some games more than others.
On Starcraft II my computer crashes about 1-2 hours after playing. On Warframe the game can crash from 5min in to 30min in.

My specs are:
CPU: i7-6700
GPU: EVGA GeForce GTX 980 SC ACX 2.0
Ram: 2x8gb kingston
Mobo: MSI Z170M-MORTAR
PSU: Corsair VS550 550W

This problem is specifically at 144Hz as I have tested on 60Hz and there are no crashes. I know my graphics card isn't overheating as I have monitored the temps right before the crash and it was only at 60-70 degrees C. It shouldn't be the motherboard or powersupply either because I've run stress test with BurnInTest and at 100% load for 1-2 hours it didn't crash.
I have also reinstalled/updated graphic card drivers to the latest version. Tested with only one monitor (I have two other monitors).
If anyone has any ideas please let me know I'm pretty lost.

 

[sizzling]

You have a low quality psu known for issues. My guess is your psu is failing under high load. The higher you push your fps the harder everything works and the more power required.

 

[sizzling]

This might be helpful http://www.tomshardware.co.uk/forum/id-2547993/psu-tier-list.html