For sale is this
Nvidia Quadro FX 4800 1792MB 1.8GB PCI-E graphics card that is compatible for the Mac Pro and the PC 

The Fastest Nvidia Video Card for the Mac Pro, with CUDA support  & Open CL Support

Better choice than a HD 5770 1GB.

OS X Display Connectivity 
Ports Supported: 2 x DVI (2560 x 1600) 
Maximum Simultaneous Displays: 2 

This is an aftermarket option, This video card is bulk stock, not retailed boxed, but will come with video card, power cables & install guide. 
This is a PC Video Card that works in a Mac Pro as well as a PC. 

YES Full boot screen is visible just like an OEM Apple Card  with mac pro 2008 & upwards


This Nvidia Quadro FX4800 1.8GB Video Card is compatible with these Mac Pro's running Lion 10.7.5, Mountain Lion 10.8+ , OSX 10.6.8, OSX 10.9.5, OSX 10.10.5 Yosemite, El Capitan 10.11.6 & Sierra 10.12, High Sierra 10.13.6

-Mac Pro 1st Generation, 2006 (must be running 10.7.5 , no boot screen)
-Mac Pro 2nd Generation, 2007 (must be running 10.7.5 , no boot screen)

  • Mac Pro (2006; MacPro1,1)
  • Mac Pro (2007; MacPro2,1)
  • Mac Pro (Early 2008; MacPro3,1)
  • Mac Pro (Early 2009; MacPro4,1)
  • Mac Pro (Mid2010; MacPro5,1)
  • Mac Pro (Mid2012; MacPro5,1)

*To find your Mac Pro model, click on the upper left Apple, then About This Mac, then More Info... The Model Identifier will be MacPro1,1 or MacPro2,1 or MacPro3,1 or MacPro4,1 or MacPro5.1. This indicates the different generations. 

What you will receive: 
-One Nvidia Video Card for the Mac Pro 
-One Mac Pro motherboard power adapter cable
-One quick start installation guide