The SAPPHIRE HD 7950 3GB OC Vapor-X Edition has a core clock speed of 950 MHz and 3GB of GDDR5 memory clocked at 5000MHz (effective). We put this custom card to the test to see how it performs in the games and how well it can overclock. With a healthy factory overclock and the Vapor-X cooler this card should perform well, but you never know unless you try it out!