Understanding and Modeling On-Die Error Correction in Modern DRAM: An Experimental Study Using Real Devices

Experimental characterization of DRAM errors is a powerful technique for understanding DRAM behavior and provides valuable insights for improving overall system performance, energy efficiency, and reliability. Unfortunately, recent DRAM technology scaling issues are forcing manufacturers to adopt on-die error-correction codes (ECC), which pose a significant challenge for DRAM error characterization studies by obfuscating raw error distributions using undocumented, proprietary, and opaque error-correction hardware. As we show in this work, errors observed in devices with on-die ECC no longer follow expected, well-studied distributions (e.g., lognormal retention times) but rather depend on the particular ECC scheme used.