Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 01 Dec 2009 17:22:00 +0200
From:      Alexander Motin <mav@FreeBSD.org>
To:        Alexander Motin <mav@freebsd.org>
Cc:        freebsd-current@freebsd.org, David Naylor <naylor.b.david@gmail.com>
Subject:   Re: FreeBSD 8.0 Performance (at Phoronix)
Message-ID:  <4B153498.8050601@FreeBSD.org>
In-Reply-To: <1259659388.00189017.1259647802@10.7.7.3>
References:  <1259583785.00188655.1259572802@10.7.7.3> <1259659388.00189017.1259647802@10.7.7.3>

next in thread | previous in thread | raw e-mail | index | archive | help
Alexander Motin wrote:
> Threaded I/O activity could get much benefit from NCQ-aware disk driver.
> It is not included in default FreeBSD kernel, but it would be nice to
> compare.

To check possible NCQ effect, I've built test setup with new 320GB
7200RPM Seagate drive connected to Intel ICH10R controller. I've run
IMHO more reasonable benchmark/raidtest tool from ports on whole device,
to execute pregenerated random mix of 10000 random-sized (512B - 128KB)
read/write requests using default ata(4) driver and new ahci(4):
Number of READ requests: 5029.
Number of WRITE requests: 4971.
Number of bytes to transmit: 655986688.
Number of processes: 32.

The results:
ata(4) - no NCQ:
Bytes per second: 12455402
Requests per second: 189
ahci(4) - with NCQ:
Bytes per second: 19889778
Requests per second: 303

Results are repeatable up to the 4-th digit. Average time per request is
5.29ms and 3.3ms respectively, that seems realistic for this drive.

-- 
Alexander Motin



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4B153498.8050601>