DRAM

Dynamic Random Access Memory (DRAM) is the dominant technology for main memory in virtually all modern computers, from smartphones to supercomputers. It stores each bit of data as an electrical charge in a tiny capacitor paired with a transistor, and because the charge leaks over time, each cell must be periodically refreshed — hence "dynamic." This refresh requirement consumes power and bandwidth, and the need to read out entire rows at a time creates a fundamental asymmetry between the speed of row access and the granularity of data retrieval.

DRAM has been the battlefield upon which the Memory Wall has been fought for three decades, and despite the emergence of HBM and other alternatives, it remains the cost-effective baseline against which all other memory technologies are measured. The Row Hammer vulnerability — in which rapid repeated access to a row can corrupt adjacent rows — reveals that DRAM's physical implementation has security implications that its logical abstraction was designed to hide.