On Fri, 22 Aug 2008, Szabolcs Szakacsits wrote: > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html