WSL 2 now offers noticeably faster Windows file‑system access.
Microsoft’s June 3 2026 build 2.4.0 introduces per‑device swiotlb pools for virtio‑fs and virtioproxy. The change reduces average file‑read latency from 1.5 ms to about 1 ms—a 30 percent improvement—according to benchmarks posted by Box of Cables. The update also adds a new configuration flag that lets users allocate separate I/O buffers per virtual device, preventing contention under heavy workloads.
The boost matters because many developers run build tools and editors inside WSL that frequently touch the Windows filesystem. Lower latency translates to faster compile times and more responsive IDEs, closing the performance gap between native Linux and the WSL environment.
While the numbers are modest, they show Microsoft is still fine‑tuning the subsystem rather than declaring it finished.