Emerging memory technologies, such as three-dimensional die-stacked dynamic random access memory (3D-DRAM) and non-volatile random-access memory (NVRAM), introduce promising opportunities in achieving high performance for computer processors. Computer servers with mixed memory technologies introduce a new multi-dimensional non-uniform memory access (“multi-NUMAâ€) method, where the computer memory hierarchy has widely varying performance and efficiency characteristics depending on the type of memory and where it resides in the system. Despite the promising benefits, multi-NUMA systems impose significant architecture design challenges due to the level of heterogeneity they introduce. The multi-dimensional heterogeneity, which ranges from access latency, bandwidth, and access granularity to reliability and functionality, makes memory hierarchy performance and access behavior difficult to predict and manipulate. Addressing these issues can influence the architecture design for building efficient multi-NUMA systems and also spawn new applications that can deal with larger volumes of heterogeneous data than what is possible at present.
This project aims to improve the performance of future server systems that incorporate mixed memory technologies. To achieve the objective, this project consists of three phases. The first phase seeks to reinvestigate the basic performance models, assumptions, and metrics of memory hierarchy architecture design, across memory system performance, reliability, and scalability, by encompassing the multi-NUMA scenario. Guided by the multi-NUMA-aware architecture design strategies, the second phase will focus on reconsidering the design of memory hierarchy architecture components that are critical to the application’s instructions-per-cycle (IPC) performance. Finally, the third phase seeks to ensure scalable IPC performance in both multi-socket and memory-fabric-based multi-NUMA systems.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.