Computer Rebooting After adding second 970

[Pjrmax]

Recently I installed a second GTX 970 in my gaming rig. I run the cards in sli. However recently my computer has been randomly rebooting while playing games. I started to keep an eye on my computer temps and when the reboots happen everything is at normal temps. (Sub-70) I don't know if it is a problem with Windows 10 which I recently installed or if my power supply is simply not keeping up. Thanks in advance for your replies.
Computer Specs
GTX 970 MEx2
Intel i7 4790k at stock speeds
24gb Ripjaw Ram
Intel 250gb SSD
WD 1TB Mechanical
MSI Z87-GD65 Mobo
Corsair 750w psu

 

[DeathRabit]

If you have CX series this is PSU issue.