Performance and Cost Regimes Beyond Hierarchical Memory Systems

This paper examines whether the elimination of volatility hierarchies can be sustained across performance and cost regimes that have historically justified hierarchical memory systems. Using a unified semiconductor memory architecture as a fixed reference, we analyze read latency, write behavior, retention stability, access uniformity, and cost scaling relative to fully realized DRAM–NAND systems. Rather than relying on device-specific benchmarks, the analysis identifies the dominant structural constraints that bound each performance domain. We show that fast, non-destructive reads, localized and deterministic writes, long-term retention without refresh, and uniform access semantics can coexist without performance degradation. Cost per bit is shown to follow a favorable scaling trajectory driven by density and integration rather than system-level overhead. These results remove the remaining technical and economic rationale for maintaining hierarchical memory designs.