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Date: Sat, 8 Dec 2012 22:51:02 -0700 (MST)
From: Warren Block <wblock@wonkity.com>
To: Dieter BSD <dieterbsd@engineer.com>
Subject: Re: FreeBSD for serious performance? (was: Re: 9.x -- New Install
 -- serious partition misalignment)
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On Sat, 8 Dec 2012, Dieter BSD wrote:

> Having a 4KiB misalignment is nothing compared with not having NCQ
> support.
...
> Speaking of alignment, I still get "partition 1 does not end on a
> track boundary" messages. FreeBSD has no clue where the track boundaries
> are and neither do I. Disks have used varying numbers of sectors/track
> for longer than FreeBSD has existed.

A. Use ahci(4):
    "The ada device driver takes full advantage of NCQ, when supported."
    Use 'camcontrol identify ada0' to check for NCQ support.

B. Use GPT, which does not have the CHS baggage.  It is easier and more
    versatile.  My systems with GPT disks don't complain about track
    alignment.  Or maybe that's ahci(4)'s doing.