I use a Sapphire ATI Radeon HD5450 (PCI-e, 1GB DDR3, HDMI, DVI, VGA, 1 GPU) Series 11166-02-20R . Attached ioreg. The "iMac"-File is from boot with clover from usb-Stick and the "MacPro3-1" from boot with installed clover (I don't know if this is a difference for analysing).