DirectPath: High performance and energy efficient platform I/O architecture for content intensive usages

With the widespread development of cloud computing and high speed communications, end users store or retrieve video, music, photo and other contents over the cloud or the local network for video-on-demand, wireless display and other usages. The traditional I/O model in a mobile platform consumes time and resources due to excessive memory access and copying when transferring content from a source device, e.g., network controller, to a destination device, e.g., hard disk. This model introduces unnecessary overhead and latency, negatively impacting the performance and energy consumption of content-intensive uses. In this paper, we introduce DirectPath, a low overhead I/O architecture that optimizes content movement within a platform to improve energy efficiency and throughput performance. We design, implement and validate the DirectPath architecture for a network-to-storage file download usage model. We evaluate and quantify DirectPath's energy and performance benefits on both laptop and small form-factor SoC based platforms. The measurement results show that DirectPath reduces energy consumption by up to 50% and improves throughput performance by up to 137%.