Integrating the base die functionality supporting high bandwidth memory stacks into an active interposer is an effective method to increase physical density while lowering cost. Yield and cost models are presented to compare conventional architectures that use a dedicated base die per stack with configurations that place the necessary logic within a shared active interposer. Yield, latency, and cost comparisons across several technology nodes, interposer areas, and memory stack configurations are discussed. Active interposers with mature technology nodes (e.g., 65 nm) can offer meaningful savings, while more advanced nodes (e.g., 11 nm) are beneficial in configurations composed of multiple memory stacks and smaller area per stack. Memory fetch latencies of passive and active interposers are compared. Integrating base die functionality into an active interposer is shown to be most effective in systems composed of multiple memory stacks and a few DRAM layers (e.g., four layers), achieving cost reductions of approximately 20%. The cost advantage diminishes with increasing number of DRAM layers.