Phoronix comparision of HAMMER, UFS, ZFS, EXT3, EXT4, Btrfs

Ivan Voras ivoras at
Mon Jan 10 13:12:46 UTC 2011

On 10/01/2011 14:07, Bruce Cran wrote:
> On Mon, 10 Jan 2011 13:49:08 +0100
> Ivan Voras<ivoras at>  wrote:
>> It depends - since ZFS is logging all the time it doesn't have to
>> seek as much; if all transactions are WRITE and given sequentially,
>> they will be written to the drive sequentially, even with full fsync
>> semantics. But 75k IOPS is a bit too much :)
> I've been doing some benchmarking using sysutils/fio recently. It seems
> that for my desktop SATA disk (a Samsung F3) around 28-30k iops is about
> the maximum, seen both on Windows 7 (NTFS) and FreeBSD (ZFS).
> FreeBSD is much more bursty compared to Windows, getting 80k iops and
> 210MB/s for a few seconds followed by several of 0.

I've also noticed it is bursty - this can be moderated by tuning 
vfs.zfs.txg.timeout and vfs.zfs.vdev.max_pending. But I think you must 
agree that 210 MB/s on a single drive looks impossible :) I get that 
much in a SAS RAID-10 configuration.

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