4DS Memory Ltd

Founded in 2007, 4DS Memory has consistently worked toward developing new memory technologies that can provide solutions for the ever-growing demand for faster and more efficient data storage. 4DS began serious development in 2014 when it first entered into a joint development agreement with HGST/Western Digital. It also had a design agreement with Infineon to develop a custom ReRAM test chip. For the first few years, the company made steady progress. But from 2021, it encountered a number of development forks, including delays and underlying technological problems such as with memory cells scaling down. Four years ago, the delays were merely delays. To give 4DS credit, the company never shied away from denying big problems were big problems, using language such as ‘long-term delay’ where it had to be used. It did address some of those problems. For instance, in 2022 4DS encountered challenges with the etch process affecting their PCMO layer. These were addressed by early 2023 through optimisations. However, the company’s sixth (and presumably last) ‘lot testing’, which was announced in June 2025, revealed unexpected or worse-than-expected results, indicating a setback and likely adjustments to development timelines.