Date: Mon, 8 Sep 1997 21:31:31 -0700 (PDT)
Message-Id: <199709090431.VAA27806@adit.ap.net>
Mime-Version: 1.0
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To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: The is world dropping MS-DOS. What about DJGPP? (Was Re:
  Quake
Cc: djgpp AT delorie DOT com
Precedence: bulk

At 11:26  9/8/1997 +0300, Eli Zaretskii wrote:
>
>On Sun, 7 Sep 1997, Nate Eldredge wrote:
>
>> It is true that the FAT file system is very antiquated. On my Linux system
>> (using e2fs), I notice *much* faster file access (especially for things like
>> un-tarring) than on DOS.
>
>How much faster?  Can you give numbers in terms of bytes/sec when
>copying files, or files per second when searching for files (as in
>"find / -name 'foobar*'")?  What kind of DOS system do you use (plain
>DOS, Windows, what version, what disk cache)?  How much RAM does your
>machine have installed?
Okay, here you go.
I ran three tests:
- unzipping djlsr201.zip (DJGPP lib src) from current directory
- running `find' from the directory afterwards
- `cat'ing a 10 MB (10000000 byte) file >nul (or /dev/null).

Cyrix 6x86 110 (P133+), 16 MB of RAM.
MS-DOS 5.0, no Windows, no disk cache, timing by 4DOS's `timer' feature,
Seagate 850MB hard drive, not defragmented recently.
unzip -q djlsr201.zip: using Info-Zip compiled with DJGPP: 5m38.06s
gfind >nul:                                                0m04.06s
cat 10meg >nul:                                            0m06.15s

Same as above, with Netware Lite's NLCACHEX in XMS memory, 1700K cache size.
unzip:                                                     2m56.32s
gfind:                                                     0m03.74s
cat:                                                       0m06.38s

Same system, Linux 2.0.29, 1.2GB Western Digital hard drive, e2fs file
system, timing by bash `time' feature (`real' time value), times included a
`sync' to make sure everything got written.
(unzip -q djlsr201.zip; sync): Info-Zip                    0m11.289s (really!)
(find >/dev/null; sync):                                   0m01.152s
(cat 10meg >/dev/null; sync):                              0m03.459s

Same as above, 340 MB Western Digital hard drive, msdos (FAT) file system
unzip:                                                     0m22.821s
find:                                                      0m03.000s
cat:                                                       0m08.350s

>The reason I'm asking is that my experience indicates that the
>differences between FAT and inode-based filesystems are *not* what
>explains how fast the file I/O works.  For example, a typical
>Windows 95 system is about twice as fast as an optimized DOS system
>(with a large SmartDrv cache) *for the same FAT disk*.  (Windows 95
>might be even faster than that if you tell it in Control Panel that
>your machine is a Network Server.)
>
>So it's not the way the filesystem is layed out on the disk that
>matters, it's how the file I/O is implemented in the OS.
It seems there is some difference, though, since Linux takes about twice as
long to do the same stuff on an msdos file system as on e2fs. I realize
they're different drives, and one may well be significantly faster than the
other. The native MSDOS loses big, although I think the drive is fairly
fragmented. (MSDOS 5.0 doesn't come with DEFRAG, and the last shareware
defragger I tried made 1-byte errors in all my files. Good thing I had a
backup...) Well, draw your own conclusions.

Nate Eldredge
eldredge AT ap DOT net