On Fri, 22 Aug 2008, Szabolcs Szakacsits wrote:

quoted text
> On Fri, 22 Aug 2008, Dave Chinner wrote:

> > On Thu, Aug 21, 2008 at 08:33:50PM +0300, Szabolcs Szakacsits wrote:

> >

> > > The 'nobarrier' mount option made a big improvement:

> >

> > INteresting. Barriers make only a little difference on my laptop;

> > 10-20% slower. But yes, barriers will have this effect on XFS.

> >

> > If you've got NCQ, then you'd do better to turn off write caching

> > on the drive, turn off barriers and use NCQ to give you back the

> > performance that the write cache used to. That is, of course,

> > assuming the NCQ implementation doesn't suck....

>

> Write cache off, nobarrier and AHCI NCQ lowered the XFS result:

>

>                                MB/s    Runtime (s)

>                               -----    -----------

>   btrfs unstable              17.09        572

>   ext3                        13.24        877

>   btrfs 0.16                  12.33        793

>   ntfs-3g unstable            11.52        673

>   nilfs2 2nd+ runs            11.29        674

>   reiserfs                     8.38        966

>   xfs nobarrier                7.89        949

>   nilfs2 1st run               4.95       3800

>   xfs nobarrier, ncq, wc off   3.81       1973

>   xfs                          1.88       3901

Retested with a different disk, SATA-II, NCQ, capable of 70-110 MB/s

read/write:
                               MB/s    Runtime (s)

                              -----    -----------

  btrfs unstable, no dup      51.42        168

  btrfs unstable              42.67        197

  ext4 2.6.26                 35.63        245

  nilfs2 2nd+ runs            26.43        287

  ntfs-3g unstable            21.41        370

  ext3                        19.92        559

  xfs nobarrier               14.17        562

  reiserfs                    13.11        595

  nilfs2 1st run              12.06       3719

  xfs nobarrier, ncq, wc off   6.89       1070

  xfs                          1.95       3786
	Szaka
--

NTFS-3G:  http://ntfs-3g.org
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