Sunlune has fused DRAM to its Ethereum-mining die using hybrid bonding, putting China’s chip industry ahead of the rest of the world in applying this technique. The resulting Jasminer X4 chip computes Ethereum hashes and delivers high-speed, DRAM-based storage while consuming little power. Ten years after its 2009 founding, Sunlune started designing an ASIC to implement Ethereum’s Ethash algorithm and received backing from Intel Capital in 2022. It began targeting blockchain-based storage networks like Filecoin by attaching DRAM to its chip. Sunlune’s bonding of memory to a logic die comes after Chinese NAND-maker YMTC surprised the industry with flash chips in which the drive circuitry and memory array were fabbed on two different die and bonded together. The X4 is a near-memory Ethereum-mining chip using attached DRAM as a storage drive. By integrating dynamic data storage and computation in the same chip, the increased parallelism improves energy efficiency. Sunlune claims a memory-access bandwidth of 1 TB/s, storage capacity of 5 GB, and processing capacity up to 65 million hashes per second (MH/s), while requiring only 23 W.