Extremely slow read/write speed, 7.1 Release on Intel ICH9 SATA

[Kenneth D. Merry]

On Thu, Feb 26, 2009 at 18:57:48 +0200, Rusu Silviu wrote:
> Extremely slow read/write speed, 7.1 Release on Intel ICH9 SATA
> 
> Should i send this to freebsd-fs list?
> 
> Have 3 HDDs
> - 160G Seagate Serial ATA v1.0, 3 partitions: 1 - system, 2 - data, 3 -
> storage, soft updates on for all partitions
> - 750G Samsung Serial ATA II, 1 partition, soft updates on
> - 1000G Samsung Serial ATA II, 1 partition, soft updates on
> 
> hw.ata.wc=1
> 
> Mobo is an ASUS P5KR, P35/ICH9
> Buyed it cause `man ata' says ICH9 is supported
> There are also Jmicron eSATA/PATA controller, that i actually disabled
> No overclocking
> 
> dd if=/dev/ad4 of=/dev/null
> iostat -w1 ad4
>       tty             ad4             cpu
>  tin tout  KB/t tps  MB/s  us ni sy in id
>   47   48  1.65 252  0.40   6  0  1  1 92
>    1  251  0.50 12650  6.18   2  0 15 14 69
>    0   88  0.50 12583  6.15   3  0 18 12 67
>    0   87  0.50 12641  6.17   3  0 18 12 68
[ ... ]

You should specify a blocksize with dd.  By default, it uses 512 byte
blocks, which will result in very slow transfer speeds.

Try this instead:

dd if=/dev/ad4 of=/dev/null bs=1m

Ken
-- 
Kenneth Merry
ken at kdm.org