Power Supply Crash with GTX 1080 TI

[HelderFlame]

Hello
I installed a Nvidia Gtx 1080 TI on my mac 2012 5.1 with Sierra to use in 3D CGI. But when i start a image render the machine power off. Always happening when i stress the GTX 1080 TI.
What you think about?
1- My Power Supply is damage?
2-I need a simultaneous second power supply exclusive for GTX 1080 to support this stress in render time? How can i install a second power supply?

Thanks
Helder

 

[P1LGRIM]

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