MSI AMD Radeon HD 7990 6144MB GDDR5 Dual-Link DVI-I x1 4x Mini DisplayPort Video Card R7990-6GD5 Graphics Engine: AMD Radeon HD 7990 Core Clock Speed(MHz): 950 (Boost: 1000 MHz) Video Memory: 6144MB GDDR5 Memory Clock Speed(MHz): 6000 Connectors: Dual-Link DVI-I x1, 4x Mini DisplayPort Display Output (Max Resolution): 2560 x 1600