Its the one with the BNC's on the front.

The way we run our system is we have 2 dvi's out of the G5 into converts to turn them into VGA as we dont have DVI monitors, and i used to use the RGBHV BNC's on the front of the CIB as my main out put because that was what i ran to the projectors.

But now the RGBVH on the front and the VGA on the rear of the CIB wont work, so i am temporarily running a second VGA feed from the dvi-vga converter.