The GeForce 8800 GT Mac Edition was a graphics card by NVIDIA, launched in February 2008. Built on the 65 nm process, and based on the G92 graphics processor, in its G92-270-A2 variant, the card supports DirectX 11.1. Even though it supports DirectX 11, the feature level is only 100, which can be problematic with many DirectX 11 & DirectX 12.
May 01, 2011 GeForce 300M series: GT 330M, GT 320M GeForce 200 series: GTX 285 for MAC GeForce 100 series: GT 120 GeForce 9M series: 9400M GeForce 8 series: 8800 GT GeForce 8M series: 8800M GTS, 8800M GS Quadro series: 4000 for Mac Quadro FX series: FX 4800 for MAC, FX 5600.
The Nvidia GeForce 8800 GT card that our new Mac Pro came with is a $200 option; it comes with 512MB of graphics memory—twice the graphics memory as the stock ATI card. The GeForce 8800 GT.
If you already own the card ... yes it should work.
But the initial boot screen and os selection screen cannot be displayed without flashing the video card. OSX must be loaded completely to get the user selection screen displayed.
To get the boot screens displayed, the video card must be flashed, http://www.macvidcards.com/ has flashing servive for many cards, ask them.
And you should install the nvidia web driver http://www.nvidia.com/download/driverResults.aspx/105589/en-us for better performance. OSX has a build in driver that captures many cards, but performance is sloooooow.