UC San Diego
Onyx : a phase-change memory storage array
- Author(s): Akel, Ameen Daniel
- et al.
This thesis describes a prototype, high-performance, solid -state drive based on first-generation phase-change memory (PCM) devices called Onyx. Onyx has a capacity of 10 GB and connects to a host machine via PCI-Express. This thesis also describes the PCM DIMMs that make up Onyx, including the PCM memory devices used, and the FPGA-based controller that manages the PCM DIMMs. This thesis provides insight into the PCM DIMM design process and shows the changes required to integrate future-generation PCM. This thesis also describes my experience with an existing wear-leveling technique, which I implemented in Onyx in order to manage wear. My results show that Onyx outperforms a state-of-the-art FusionIO ioDrive flash memory SSD for both reads and small writes. Also, I show that Onyx also incurs significantly less CPU overhead per IOP for small requests, which has the advantage of saving power. My results also show that a first-generation PCM- based SSD performs on par with a flash-based SSD in real- world workloads. As part of my study, I address the performance impact of start-gap wear-leveling in Onyx