I made a proper install of Mavericks on my PC everything was working fine and today when I booted my OS X partition it shutdown after the greyscreen.
I've already repaired the permissions with the usb key partition.
I've tried to start with -x -v but it don't event boot here is the screenshot of what I got.
Here is my config :
Intel Core i5-2500K 3.3GHz
ASUS Maximus IV Gene-Z
SSD OCZ Vertex3 120Gb
AMD Radeon R9 270X
Thank for your help.