Messages in this thread | | | Date | Fri, 22 Aug 2008 15:44:29 +0300 (MET DST) | From | Szabolcs Szakacsits <> | Subject | Re: XFS vs Elevators (was Re: [PATCH RFC] nilfs2: continuous snapshotting file system) |
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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
Szaka
-- NTFS-3G: http://ntfs-3g.org
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