Computer crashes during high loads (PC Gaming, rendering)

[marmelade912]

I built a PC this year around February, and whenever I try to start Crysis 3 or render a video (very high loads), my computer instantly crashes.
My build:
i7 4790k (not overclocked)
H100i cooler (fans are well placed around 450D case, and no cables prevent ventilation)
GTX 980 (also not overclocked)
Seagate 1TB HDD
Crucial 128GB SSD
EVGA SuperNOVA 850G2

Wiring seems to be fine, but this is my first computer I've ever built. Is this due to hardware issues or is there any other issues that may be the cause of this?

 

[animal]

Have you checked your CPU/GPU temps while running high loads?

 

[marmelade912]

Have you checked your CPU/GPU temps while running high loads?

Sorry for the late response, I haven't had to deal with this problem again until today, and for the most part I have just been ignoring it.

The highest my CPU has reached is around 55 degrees celsius, but if idle or not using for games it's usually around 26-33 degrees celsius. As for my GPU, the temps always stay around 30-40 degrees celsius. I don't think that temps are the problem for me, because I noticed even today that when I tried adding images on Prezi my computer would do the same thing as it did when I tried playing Crysis 3 or rendering videos. As soon as I clicked "Images" (http://i.gyazo.com/0ea0c4ee16006e74f685ceffd167a11e.png) my computer shuts down and reboots. I'm assuming it's an issue with my HDD, but when moving or accessing files in other programs it always works fine.