The powerlink is designed to provide both a more stable power source and reduce ripple and noise, compared to connecting your power supply directly to the graphics card.
The powerlink has another function: to make your PC look even more awesome. This adapter allows you to reroute the power inputs for your graphics card, giving you improved case airflow, A lower profile height, and best of all, cleaner wiring setup. For maximum stability, and it won't affect your overclock!