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Date: Wed, 15 Apr 2009 13:54:13 +0200 (CEST)
From: Alexander Best <alexbestms@math.uni-muenster.de>
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Subject: hard drive performance
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hi there,

i have 2 hard drives running. the first one is SATA300 and the other one
UDMA100. here are the dmesg entries:

ad0: 238474MB <SAMSUNG SP2504C VT100-50> at ata0-master SATA300
ad1: 157066MB <Hitachi HDS722516VLAT80 V34OA63A> at ata4-master UDMA100

i've tried to test the drives' performances using the following commands:

dd if=/dev/ad0 of=/dev/null bs=1m count=300
and
dd if=/dev/ad1 of=/dev/null bs=1m count=300

the results are:
ad0 = 314572800 bytes transferred in 4.325645 secs (72722751 bytes/sec)
ad1 = 314572800 bytes transferred in 5.166126 secs (60891430 bytes/sec)

the results for ad0 are a bit disappointing though. is this normal or is bs=1m
wrong?

cheers.
alex