Solid-State Memory Capacity and Bandwidth

Chapter 5 traces the evolution of solid-state memory, highlighting exponential growth in capacity and bandwidth driven by Moore’s law and key innovations. Early computers like ENIAC relied on vacuum tubes, offering only 83 bytes of storage. Magnetic core memory dominated until the mid-1970s, followed by SRAM for speed-critical tasks. The pivotal breakthrough came with DRAM, invented by Robert Dennard in 1968, with Intel’s 1103 chip debuting in 1970. DRAM’s simple design—one transistor and one capacitor per cell—enabled high density and low cost, though periodic refresh was required. Successive milestones included CMOS DRAM (1979), synchronous DRAM (1992), and DDR SDRAM (2000), which doubled data transfer rates. Later generations (DDR2–DDR5) and high-bandwidth memory (HBM) introduced 3D stacking and through-silicon vias, vastly improving performance for data-intensive applications. Both capacity and bandwidth have grown exponentially, making modern memory essential for high-performance computing and graphics.