Die-Stacked DRAM Caches for Servers
Recent research advocates using large die-stacked DRAM caches to break the memory bandwidth wall. Existing DRAM cache designs fall into one of two categories - block-based and page based. The former organize data in conventional blocks (e.g., 64B), ensuring low off-chip bandwidth utilization, but co-locate tags and data in the stacked DRAM, incurring high lookup latency. Furthermore, such designs suffer from low hit ratios due to poor temporal locality. In contrast, page-based caches, which manage data at larger granularity (e.g., 4KB pages), allow for reduced tag array overhead and fast lookup, and leverage high spatial locality at the cost of moving large amounts of data on and off the chip.