For decades, storage has been the bottleneck of computing. Even the fastest NVMe SSDs are crippled by latency measured in microseconds, while the CPU operates in nanoseconds. The first two generations of RAM caching offered a solution: use system memory as a high-speed buffer. But they came with a fatal flaw—volatility.
9/10 – revolutionary but hardware-gated. Note: As of April 2026, check for commercial implementations like "PrimoCache 5" or "Intel VROC 4.0" that may incorporate similar features under different names. ramcache 3
Will it replace ZFS ARC or L2ARC? No – those are filesystem-level caches. Ramcache 3 operates below the filesystem, caching entire block devices. It is a complementary technology. For decades, storage has been the bottleneck of computing
For early adopters with persistent memory hardware, Ramcache 3 closes the last remaining gap between DRAM speed and storage safety. For everyone else, it offers a glimpse of a future where “save your work before shutdown” becomes an obsolete phrase. But they came with a fatal flaw—volatility