Optiplex 990 (Radeon 5450 512MB )Integrated into SSDT Radeon 5450 512mb GPU Card � Fully Install With EFI � 60FPS Max �Bench Tested in HiDPi Mode
��For install Big Sur change Mac Version to a newer version or it will say MAC OS version not good.
��Radeon Works for all MacOS except after 10.14 you need to Patch Kext it wont work right out the box .
For The built-in Hd2000 GPU Theres no Support in no MacOs Version .�Only works with digital D-Sub Connector no VGA Support on newer MacOS