Sapphire   Radeon HD 7990 6GB DDR5 DVI-I/Quad Mini DP PCI-Express   Game Edition Graphics Card 21207-00-50G Display Support: 5 x Maximum Display Monitor(s) support Output: 4 x Mini-DisplayPort; 1 x Dual-Link DVI-I GPU: 950(Boost:1000) MHz Core Clock Video Memory: 768(384-Bit X2) -bit GDDR5; Effective 6000 MHz Memory Clock Crossfire Support: Native Hardware Crossfire; External Power: PCIe Graphic External 2 x 8 pin