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From: mwm@eris.BERKELEY.EDU (Mike (My watch has windows) Meyer)
Newsgroups: comp.sys.amiga
Subject: Disk timings....
Message-ID: <3406@jade.BERKELEY.EDU>
Date: Fri, 1-May-87 06:44:39 EDT
Article-I.D.: jade.3406
Posted: Fri May  1 06:44:39 1987
Date-Received: Sun, 3-May-87 06:01:02 EDT
Sender: usenet@jade.BERKELEY.EDU
Reply-To: mwm@eris.BERKELEY.EDU (Mike (My watch has windows) Meyer)
Organization: Missionaria Phonibalonica
Lines: 86


In the process of buying a hard disk, I dug out the disk performance
tester on Fish disk 48, and ran it on the disks I could get my hands
on. I also added some other odds and ends, like the 33.47 ram: driver
(why does it write noticably slower than the 33.46 one? Slow ram
expansion?), the katin vdk:, and the fastest disk system I could get
my code on (well, second fastest. I may have more numbers later, as we
are probably going to investigate the new VAX I/O architechtures. Let
me know if you're interested).

The Xebec drive appears to do file creations/deleteions noticably
slower than anything else; I suspect that that is due to it using a
larger buffer (1K vs. 512), but I don't have proof that it's doing
that. Someone like to comment on this?

Likewise, the slow speed of VAX writes on small buffers is
attributable to using an 8k/1k file system, meaning you copy the data
up to twice on 4096 byte buffers, and up to 8 times on the 512 byte
buffers. I don't know what the block/frag size for the Sun was.

Those who doubt that AmigaDOS does good things for finding files vs.
the Unix file system might check out the file creations/deletions #'s
vs.  raw throughput. Now, if someone could explain why scanning a
directory is so mach faster relative to the raw disk speed on
AmigaDOS, I'd appreciate it. Numbers of opens/sec would be
interesting. I may hack the diskperf program to do that.

Finally, based on these numbers, I bought the Xebec drive. I'll have
more to say about that early next week.

	<mike

disk		file creations	file deletions	directory scan	seek and read
system		per second	per second	entries/second	per second

df1:		<=1		1		38		2

vdk: (katin)	7		90		78		*
vd0: (asdg)	18		43		51		132
ram: (33.46)	5		10		5		51
ram: (33.47)	5		10		5		51

CLtd		7		15		50		40
Microbotics	4		8		45		34
Xebec		2		3		45		49

Sun 3/50	6		11		350		298
VAX 8800 (kdb)	13		29		1629		1914

				Disk throughput in bytes/second
disk		-- read with buffer sizes: --	-- write with buffer sizes: -
system		512	4096	8192	32768	512	4096	8192	32768

df1:		11014	12024	12080	12136	4974	5180	5170	5190

vdk: (katin)	218453	655360	655360	873813	79437	113975	113975	119156
vd0: (asdg)	70849	109226	113975	119156	46811	63937	65536	67216
ram: (33.46)	201649	655360	873813	873813	137970	262144	291271	327680
ram: (33.47)	201649	655360	873813	873813	131072	238312	262144	262144

Cltd		17133	17133	17133	17133	12603	13512	13653	13797
Microbotics	14169	15984	16282	16384	9463	9602	9676	9745
Xebec		32363	37991	37991	37991	12663	13239	13512	13639

Sun 3/50	240499	234057	233189	236343	215166	182466	179755	187580
VAX 8800 (kdb)	449389	421679	419990	410669	146585	183960	185807	191812

Notes:
	(1)	vd0: & Cltd done under 1.2 release 33.46.
	(2)	Microbotics, Xebec and vdk: done under 1.2 release 33.47
	(3)	ram: don on 1.2, with the release in parens for comparison.
	(4)	df1: tests done after "addbuffers 32" & fresh formatted disk
	(5)	vd0: tests done with 2Mb recoverable ram disk, nearly full.
	(6)	ram: tests done with ASDG ram attached and active for ram: use
	(7)	All 33.46 Amiga timings done by Fred Fish.  Sun-30/50 timings
		by Rick Spanbauer.
	(8)	33.47 Amiga and VAX 8800 timings done by Mike Meyer.
	(9)	The Sun timing shows you what a high-perforamance system
		talking to a SCSI can do. The VAX timing shows what a
		high-performance I/O system can do.
	(*)	The vdk: driver would couldn't create the file for this test.
--
Take a magic carpet to the olden days			Mike Meyer
To a mythical land where everybody lays			ucbvax!mwm
Around in the clouds in a happy daze			mwm@berkeley.edu
In Kizmiaz ... Kizmiaz					mwm@ucbjade.BITNET