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Date:   Fri, 3 Sep 2021 10:48:18 -0700
From:   Eric Biggers <ebiggers@kernel.org>
To:     Szabolcs Szakacsits <szaka@tuxera.com>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Theodore Ts'o <tytso@mit.edu>,
        Matthew Wilcox <willy@infradead.org>,
        "Leonidas P. Papadakos" <papadakospan@gmail.com>,
        Konstantin Komarov <almaz.alexandrovich@paragon-software.com>,
        zajec5@gmail.com, "Darrick J. Wong" <djwong@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Hans de Goede <hdegoede@redhat.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Miklos Szeredi <miklos@szeredi.hu>
Subject: Re: NTFS testing (was: [GIT PULL] vboxsf fixes for 5.14-1
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On Fri, Sep 03, 2021 at 01:09:40AM +0300, Szabolcs Szakacsits wrote:
> User space drivers can have major disadvantages for certain workloads 
> however how relevant are those for NTFS users? Most people use NTFS for 
> file transfers in which case ntfs-3g read and write speed is about 15-20% 
> less compared to ext4. For example in some quick tests ext4 read was 
> 3.4 GB/s versus ntfs-3g 2.8 GB/s, and write was 1.3 GB/s versus 1.1 GB/s.

Your company's own advertising materials promoting your proprietary NTFS driver
(https://www.tuxera.com/products/tuxera-ntfs-embedded) claim that NTFS-3G is
much slower than ext4:

	Read:
		NTFS-3G: 63.4 MB/s
		ext4: 113.8 MB/s
		"Microsoft NTFS by Tuxera": 116 MB/s

	Write:
		NTFS-3G: 16.3 MB/s
		ext4: 92.4 MB/s
		"Microsoft NTFS by Tuxera": 113.3 MB/s

I'm not sure why anything you say should have any credibility when it
contradicts what your company says elsewhere, and your company has a vested
interest in not having proper NTFS support upstreamed to compete with their
proprietary driver.  (Note that Tuxera doesn't provide much support for NTFS-3G;
most of their efforts are focused on their proprietary driver.)

- Eric