Architectural Impacts of RFiop: RF to Address I/O Pad and Memory Controller Scalability

Abstract

Abstract-Despite power boundaries, Moore's law is still present via scaling the number of cores, which keeps adding demands for more memory bandwidth requested by these cores. To obtain higher bandwidth levels it is fundamental to address memory controller (MC) scalability. However, MC scalability growth is limited by I/O pin counts scaling. To underline MC and pin scaling, a radio frequency( RF) I/ O pad-scalable packagebased (RF iop) memory organization is further investigated.In RF iop, a radio-frequency pad (RFpad) is defined as a quilt-packaging (QP) coplanar waveguide (CPW) employed at radio-frequency (RF) ranges. An RFpad connects a rank to an RFMC which is formed by coupling MCs to RF TX/RX. By using QP package to explore the architectural benefits of laying out ranks, RF iop replaces the traditional memory path with an RFbased one, whilst exploring the scalability of RFpads/RFMCs via RF signaling. When evaluating RF iop, our findings show that bandwidth/performance are enhanced by around 4.3x which can be viewed as a diminution in transaction queue occupancy/latency as well as using a reduced and scalable 4-8 RFpads per RFMC. RF iop architectural area benefits allow bandwidth/performance improvements of around 3.2x, whilst reducing interconnection energy up to 78%.

Optically Connected Memory for Disaggregated Data Centers

“…Figure 2 shows the IO requirements in the memory controller for electrical [37], and optical interconnects to achieve a specific aggregated bandwidth. We define IO as the number of required electrical wires or optical fibers in the interconnects.…”