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Date:      Mon, 27 Jan 1997 20:52:47 +1100
From:      Bruce Evans <bde@zeta.org.au>
To:        bde@zeta.org.au, michaelh@cet.co.jp
Cc:        dicen@hooked.net, freebsd-hackers@freebsd.org
Subject:   Re: What is the default for async in /etc/fstab?
Message-ID:  <199701270952.UAA32722@godzilla.zeta.org.au>

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>> In my tests, ext2fs is fastest for huge sequential i/o's when the block
>> sizes are closer (8K vs 4K), but there was only a small difference (less
>> than 10%) between the best and worst cases (best: ext2fs under FreeBSD,
>> next: ext2fs under Linux, worst: ext2fs under Linux) except for rewrite,
>
>next: and worst: are the same here.  ;-)

Oops.  worst: ufs under FreeBSD.  Here is the data.

Environment:
- ASUS P5/133, 32MB, 2.1GB Quantum FireballTM IDE drive with identical
  configurations under FreeBSD and Linux (16 sectors/interrupt, 32-bit i/o,
  PIO mode 4).
- all on the same empty partition (except mke2fs puts lost+found there)
  at offset about 320MB and size about 1024MB.
- I thought I used the same block size of 4K in all cases, but some of
  my notes say that I used 8K for ufs.  The ufs fragment size was certainly
  not 4K as it should have been to match the ext2fs fragment size.

bonnie.ext2fs-under-freebsd-current (fs block size 4K)
-----------------------------------
              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
          512  3786 71.8  5220 18.7  1556  9.1  3904 70.7  5204 14.5  47.6  2.8

bonnie.ext2fs-under-linux-2.0.20 (fs block size 4K)
--------------------------------
              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
          512  3836 96.2  4517 25.0  2500 35.0  3488 91.2  5156 19.8  44.8  2.0

bonnie.ufs-under-freebsd-current (fs block/frag size 8K/1K or 4K/?)
--------------------------------
              -------Sequential Output-------- ---Sequential Input-- --Random--
              -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
Machine    MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  /sec %CPU
          512  3543 70.9  4627 19.1  1459  8.1  3891 70.5  4875 13.4  45.0  2.6

Bruce



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