The graphics card is determined by the model type of the unit. With the FULL model number of the unit (4 digits dash 3 alphanumeric) and the serial number I can check.
The comment on the ATI card is not correct - it could be one of many, including an nVidia board and Intel on board. All dependant on the model type. Post that info and I can tell you.
2007 Z4 3.0si