open terminal and type
ioreg | grep ATY
ioreg | grep ATY
| | | +-o ATY,Baboon@0 <class AtiFbStub, id 0x1000002ee, registered, matched, active, busy 0 (227 ms), retain 7>
| | | | +-o ATY_Baboon <class ATIFramebuffer, id 0x1000002f6, registered, matched, active, busy 0 (148 ms)...