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Is the 'hdparm' command giving incorrect results?

Posted: Tue Jul 17, 2007 4:49 pm
by impulse()
This is probably more hardware related than Linux related.

I stumbled upon the 'hdparm' command today which I was very impressed with, I soon got onto speed testing every HDD I had access to. I noticed strange results on 1 server though, it had 2 HDD, 1 SATA and 1 IDE but the IDE was returning a higher read speed. Here are my results, hopefully somebody could explain the reasons for these:

hdparm -t /dev/sda1
/dev/sda1:
Timing buffered disk reads: 100 MB in 1.54 seconds = 65.04 MB/sec

hdparm -t /dev/hdb1
/dev/hdb1:
Timing buffered disk reads: 226 MB in 3.02 seconds = 74.84 MB/sec

Posted: Tue Jul 17, 2007 5:05 pm
by Jenk
What cache does each disk have?

Posted: Tue Jul 17, 2007 5:11 pm
by impulse()
Can this be told with the hdparm command?

Posted: Tue Jul 17, 2007 5:28 pm
by volka
Take a look at http://www.tomshardware.com/de/festplat ... 11-16.html and compare the first and the last diagram.
s-ata doesn't automatically mean "always faster than ide" ;)