About Pci-e Riser
A PCI E riser is a computer cable typically used to link several video cards at once to one motherboard. By lifting them off the motherboard, the riser creates sufficient space to achieve this, and also allows for efficient cooling, which can prolong the life of any card, and potentially allow for faster processing speeds.
Your motherboard will usually have PCI slots in one of two sizes: PCI-E 1X or PCI-E 16X. If you are adding a PCI E riser to an existing set-up, make sure you choose the correct size for the available port, and the best available port for your purpose. A video card in the 16X port will allow for as many as 16 connections to the motherboard, which can significantly improve performance in gaming environments. The single port is less suitable for gaming but will be just as efficient as the 16X for simpler executions such as GPU mining. You won't need additional drivers to use your PCI E riser.
Some cables are powered, which means they have an inbuilt Molex connector. This allows them to draw power from an external source rather than draining the motherboard's power supply. Some people choose PCI E risers with a powered connector, which can certainly help if you have four or more video cards connected to one motherboard, but is not absolutely essential. All recently-made high-performance video cards use PCI-E power supply connections, and some motherboards have their own built-in Molex connector, removing the need for a powered riser.