John Carmack muses using a long fiber line as as an L2 cache for streaming AI data — programmer imagines fiber as alternative to DRAM

John Carmack suggests using a long fiber line as an L2 cache for streaming AI data, envisioning it as an alternative to DRAM due to its near-zero latency and high bandwidth capabilities. With single mode fiber speeds reaching 256 Tb/s over 200 km, Carmack calculates that 32 GB of data can be stored in the fiber itself at any given time. While the concept faces challenges like cost and energy consumption, the use of fiber could lead to significant power savings compared to DRAM. Carmack also hints at a more practical approach involving flash memory chips directly wired to AI accelerators, potentially paving the way for a standardized interface between flash and AI accelerator manufacturers.