Amazon.com: AMD Radeon R9 280X 3GB HDMI PCI Express Video Graphics Card for Apple Mac Pro, outperforms ATI Sapphire Radeon HD 2600, 4870, 5770, 7950, 9000, 9800 Gigabyte : Electronics
GIGABYTE Radeon R9 280X Video Card - 3GB GDDR5, PCI-Express 3.0 (x16), Overclocked - GV-R928XOC-3GD REV2 at TigerDirect.com