Rust In-Memory Filesystem Performance: Surprisingly, It Doesn't Matter
2025-08-25
While building a CLI tool in Rust, the author attempted to use an in-memory filesystem for faster file management tests. After exploring crates like `vfs` and `rsfs`, the surprising conclusion was that modern SSDs and OS filesystem caching are so efficient that there's virtually no performance gain from using an in-memory filesystem. Benchmarks consistently showed around 45ms for tests using in-memory filesystems, regular filesystems, and even a ramdisk—a stark contrast to expectations. The author invites readers to share examples where using an in-memory filesystem yields noticeable performance differences.
Development
in-memory filesystem