Before you purchase this graphics card, please check the following:
This GeForce 8800 GT graphics card is designed for a 1st generation (original) Mac Pro system.
PLEASE NOTE: This card is not compatible with a 2nd generation system.
If you have a 2nd generation system, please visit the Apple Store to upgrade.
To determine which system you have check the Model Identifier and the Bus Speed values in the System Profiler on your Mac Pro.
To access the System Profiler, go the Apple icon in the upper left corner of the screen on your Mac Pro and select "About This Mac". Click on the "More Info…" button to display the Profiler.