GTX 760 is crashing

I recently purchased a GeForce GTX 760 EVGA superclocked edition and since i've installed it in my rig when I try to play a game on any settings but the bare minimum it crashes and I have to reboot the machine. What am I doing wrong?

Computer specs:

-GeForce GTX 760 EVGA superclocked edition

-AMD FX-4100

-WD 1200 rpm 2TB HDD

-450W Rosewill PSU with a Dell 250w PSU powering the graphics card

-BIOSTAR A880GZ motherboard

 

It really sounds like the gpu isnt being fed enough amps. To rule this out, try doing something that doesnt take 100% gpu usage. I'm betting it can stay afloat then.

You have 2 psu's?

heh. the 250W psu probably doesnt have all its juice going to that specific PCIE molex.

But it was a brave effort!

yea under load the gpus can get near 300w

I would get a real PSU IMMEDIATELY. You are going to fry your shit with that jerry rig you have going. I would never run my stuff of a Dell PSU.