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From: Bill Davidsen <davidsen@tmr.com>
To: Paa Paa <paapaa125@hotmail.com>
Cc: nickpiggin@yahoo.com.au, linux-kernel@vger.kernel.org
Subject: Re: Lower HD transfer rate with NCQ enabled?
Date: Fri, 06 Apr 2007 17:33:09 -0400	[thread overview]
Message-ID: <4616BC95.8070009@tmr.com> (raw)
In-Reply-To: <BAY20-F2534ADD292CC02D5ACAFBCF9670@phx.gbl>

Paa Paa wrote:
>>> Q: What conclusion can I make on "hdparm -t" results or can I make 
>>> any conclusions? Do I really have lower performance with NCQ or not? 
>>> If I do, is this because of my HD or because of kernel?
>>
>> What IO scheduler are you using? If AS or CFQ, could you try with 
>> deadline?
> 
> I was using CFQ. I now tried with Deadline and that doesn't seem to 
> degrade the performance at all! With Deadline I got 60MB/s both with and 
> without NCQ. This was with "hdparm -t".
> 
> So what does this tell us?
> 
It suggests that it's time to test with real load and see if deadline 
works well for you in the general case.

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot

  parent reply	other threads:[~2007-04-06 21:31 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-04-03  7:11 Lower HD transfer rate with NCQ enabled? Paa Paa
2007-04-03  9:18 ` Nick Piggin
2007-04-03 21:31   ` Paa Paa
2007-04-04  2:06     ` Nick Piggin
2007-04-06 21:33     ` Bill Davidsen [this message]
2007-04-03 16:31 ` Chris Snook
2007-04-03 16:47   ` Mark Lord
2007-04-03 19:17     ` Phillip Susi
2007-04-04 15:36       ` Mark Lord
2007-04-05 15:30         ` Phillip Susi
2007-04-05 16:11           ` Mark Lord
2007-04-05 16:45             ` Lennart Sorensen
2007-04-09 14:46             ` Phillip Susi
2007-04-10  3:58               ` Mark Lord
  -- strict thread matches above, loose matches on Subject: below --
2007-04-05 16:26 Paa Paa

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