Computer shuts down after some minutes

[Googolplex]

I finally got new PC components and build up a new machine!

Intel Core i7-4770 "Haswell" @3,40 GHz
16GB Kit G.Skill Ares DDR3-RAM 1600 CL9
256GB Plextor SSD + 1TB WD Caviar Blue HDD
750W BeQuiet! Dark Power Pro 10
Gigabyte GA-Z87X-UD4H Motherboard
nVIDIA GeForce GTX 560 Ti (my old one)


CPU temps are at 30°C Idle and 65°C Load using a Thermalright True Spirit 140 BW cooler.

Now I am able to play the pigs!


My old CPU was at 70°C in Idle and 96°C Load. This was causing the shut downs.