Blackscreen with Mavericks

[Krissy]

Hello guys,
I tried to install Mavericks on my PC:

I7 990x (not OCed)
Gigabyte GA-X58A-UD7
Nvidia GTX 590 (Two GPU on one Card)

After choosing the USB stick the Apple logo came up, but nothing happened. Just a blackscreen
Can anyone help me? Any ideas?

 

[stubbz]

try with adding this boot flag:

GraphicsEnabler=Yes npci=0x3000 PCIRootUID=0