Radeon HD 5770 1GB for Mac

http://www.amd.com/en-us/products/graphics/desktop/5000/5770 

 

For impressive graphics processing power, the ATI Radeon HD 5770 with 1GB of GDDR5 memory is a great choice for visual creative, scientific, and technical applications. ATI Radeon HD 5770 includes three video ports: two Mini DisplayPorts and one dual-link DVI port. This allows you to connect the 24-inch Apple LED Cinema Display plus another Mini DisplayPort-based display, and a DVI-based display such as the 30-inch Apple Cinema HD Display.