Defective GPU?

[sn0wball]

Hello, I've recently purchased a Palit GTX 670 2GB graphics card and have run a few benchmarks to test it.
My GPU scores are lower than they should be however. I score 20000 with 3DMark Vantage when it apparently should be 25000. My CPU score is fine.
I've also noticed faint wavy lines on the bottom of my screen that appear when playing games. I've disabled the GPU, checked my iGPU and the wavy lines do not appear. Should I send it back?

System specs:
i5 3570k
Asus P8Z77-V Pro
8GB Corsair Vengeance RAM
Corsair TX750 PSU
Palit GTX 670 2GB

 

[akamrcrack]

yeesss

 

[sn0wball]

I should add that these wavy lines are only visible on a black screen.