[HELP!] Mavericks Bootloader only works with usb-stick..! P8Z77-M PRO + ASUS HD 7950

[Sampsukka]

[FIXED] ASUS HD7950-DC2T-3GD5-V2 works only in safemode!

Hello folks! I need your help... I have tried everything and there's no solution. My computer only runs bootloader with usb-stick. (including 7950)
When I don't use it, only iGPU graphics (HD4000) works, but with Asus radeon hd 7950 doesn't load and it puts me this error screen (pic from below):

So could you please tell me what BIOS settings should I use and what should I enable/disable in multibeast?
Thank you for advance.

 

[Sampsukka]

Okay now I have realized that it's working perfectly with integrated graphics in bootloader section. And after I have booted into mac, switched hdmi cable to the 7950, it works! so the only problem is... how to get 7950 working in bootloader?