NTSYNC lands Windows thread-synchronization primitives natively in the Linux kernel, reducing Wine/Proton emulation overhead and fixing correctness bugs.
Key Takeaways
NTSYNC is a Linux kernel driver implementing Windows NT sync objects natively; authored by CodeWeavers’ Elizabeth Figura, shipped in stable SteamOS March 2026.
Linux crossed 5% of Steam users for the first time in March 2026, driven by Windows 10 EOL and Steam Deck adoption.
Headline 40-200% FPS gains compare against unmodified upstream Wine; gains over Proton’s existing fsync are modest but correctness fixes are real.
Valve shipped NTSYNC despite engineer Pierre-Loup Griffais saying fsync was already fast enough, citing edge-case hitches and deadlocks fsync caused.
NTSYNC continues a pattern: Linux previously added WaitForMultipleObjects-equivalent primitives for Wine compatibility; kernel-level Windows API parity is an ongoing strategy.
Hacker News Comment Review
Commenters note the real value is correctness, not raw FPS: fsync produced subtle deadlocks and hitches in specific games that benchmarks never captured.
Developer experience with WaitForMultipleObjects highlighted a genuine API gap between Windows and Linux that took decades and gaming pressure to close.
MS indifference seen as structural: commenters argue no one inside Microsoft gets promoted by slowing Linux gaming, with cloud revenue the priority.
Notable Comments
@Animats: Wine’s allocator held a futex lock during realloc, causing multi-thread futex congestion that dropped some Rust programs from 60 FPS to 0.5 FPS, fixed in Wine 11.0.
@mifydev: Predicts NTSYNC evolves into a full ntoskrnl.ko, effectively a “Linux Subsystem for Windows” with near-zero Windows API overhead.
