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From: Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl>
To: Tim Kientzle <tim@kientzle.com>
Subject: Re: IBM blade server abysmal disk write performances
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>>
>> 10000+0 records in
>> 10000+0 records out
>> 5120000 bytes transferred in 60.024997 secs (85298 bytes/sec)
>
> What exactly was the 'dd' command you used?
>
> In particular, what block size did you specify?

5120000/10000=512

default

if it takes one revolution for one write it means that write caching is 
disabled.

that's all.

linux always uses buffered devices, only relatively recently special 
OPTION was added to have raw ones. Complete nonsense but it's linux.