This post is from the WWDC26 File Systems Q&A.
Are there new file-system APIs in macOS 27 that improve performance when writing frequent real-time monitoring logs?
Real-time monitoring logs
What sort of performance improvement are you looking for? Can you be a bit more specific about what the problem is? If appending to an existing log file, you can improve performance ahead of time if you can preallocate disk space in larger units ( if you know you will use the disk space eventually). To be a good citizen you should clip the unused blocks back and donate to the system when no longer writing.