NVMe Flash-based SSDs are widely deployed in data centers to cache working sets of large-scale web services. As data centers face increasing sustainability demands, such as reduced carbon emissions, efficient management of Flash overprovisioning and endurance has become crucial. Our analysis demonstrates that mixing data with different lifetimes on Flash blocks results in high device garbage collection costs, which either reduce device lifetime or necessitate host overprovisioning. Targeted data placement on Flash to minimize data intermixing and thus device write amplification shows promise for addressing this issue.

Currently, there are two representative non-volatile dual in-line memory module (NVDIMM) interfaces: a proprietary Intel DDR-T and the JEDEC NVDIMM-P, which are not supported by existing platforms. Adoption of new platform is costly and measuring its efficiency of migrating to the new platform is much more complex. This study is an alternative way of them—finding a new memory device that can be supported by all existing systems. In this paper, we propose an NVDIMM architecture with several system-wide mechanisms to allow the synchronous DDR4 memory interfaces to support non-deterministic (asynchronous) timing. The proposed memory architecture is implemented as a real device prototype, and also evaluated using synthetic and real workloads on an x86-64 server system.

We consider a Machine-to-Machine (M2M) network where a large number of user nodes (STAs) communicate with a Data Collector (DC). We consider the case where all the user nodes periodically transmit their data packets to the DC and the network is in saturation. Recently protocols based on Frame Slotted Aloha (FSA) have been shown to be suitable as MAC protocols for M2M data collection networks under saturated conditions. It can be shown that implementing Multi-Packet Reception (MPR) capability to the DC improves the performance of the FSA protocol. In this work we propose a Multi-Packet Reception (MPR) based FSA (MPR-FSA) protocol and study its performance. We derive the asymptotic limits of throughput, delay and energy efficiency based on MPR-FSA protocol. We also derive the limiting value of MPR (Klim) parameter for a given FSA based data collection network at which asymptotic performance is achieved. A mathematical model is proposed and the analytical values are validated using extensive simulations.