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Comment by billziss | Hacker News Reader

I am the author of WinFsp and I believe you are missing the point or you did not actually read the article. Early on I say that:

<< This performance testing shows that WinFsp has excellent performance in all tested scenarios. It outperforms NTFS in most scenarios (an unfair comparison as NTFS is a disk file system and WinFsp is tested with an in-memory file system). It also outperforms Dokany in all scenarios, often by an order of magnitude. >>

My intent was to measure performance of WinFsp against NTFS in order to establish a baseline and to show that building file systems in user mode is not as inefficient as people think.

You should also note that a hacker news submission is only 80 characters and it is hard to clearly communicate one's intentions fully.

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I read the article, and the quoted sentence. This is the reason why I find your HN submission title intentionally misleading.

It's a cool project, and this deception is entirely unnecessary.

Why not claim "FASTER than Dokany".

An interesting comparison would be ntfs-3g on WinFst vs. native NTFS either both on RAM drive or Disk.

You also did not answer any of the questions in my comment.

I will change the title to say "Faster than Dokany" without mentioning NTFS.

The deception is not intentional. For me it was important to verify that my project is not slower than NTFS when using my test file system, which is an in-memory file system. You may notice that Dokany is actually slower or on par with NTFS in many scenarios even with an in memory file system.

Trying NTFS on a RAM disk is a good idea. I simply did not think of it.

There is no on disk implementation of WinFsp that I can share at this moment.

Please let me know if you have other questions.

Your comments make a fair point. NTFS is in fact effectively an in-memory filesystem when you have caching, and not going out to disk to satisfy various requests.

It's a valid observation that we can have a filesystem that trombones out to user space to (say) fetch a block of data, and (contrary to what some might expect) it doesn't perform worse than an in-kernel one which gets it from a cache.

> NTFS is in fact effectively an in-memory filesystem when you have caching, and not going out to disk to satisfy various requests.

It is interesting to see that NTFS is doing extremely well in a few different tests that are entirely satisfied from the cache: the list directory operation and the cached read/write operations. OTOH it does not do as well in tests that could potentially be satisfied from cache (like file open tests).

In any case I intend to retry the tests using NTFS on a RAM disk when I get some time.

You should better say that your userland FS is fast with WinFSP that with Dokan https://news.ycombinator.com/item?id=13129215

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