*BSD News Article 25488


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From: amurai@tama.spec.co.jp (Atsushi Murai)
Newsgroups: comp.os.386bsd.misc
Subject: Re: Experience with double-speed CD drives? (esp Toshiba 3401b)
Message-ID: <AMURAI.94Jan1162707@tama.spec.co.jp>
Date: 1 Jan 94 21:26:53 GMT
References: <1993Dec31.202224.813@cs.wisc.edu>
Sender: amurai@tama.specgw.co.jp (Atsushi Murai)
Organization: System Planning and Engineering Co.,Ltd
Lines: 43
In-Reply-To: jcargill@oka.cs.wisc.edu's message of 31 Dec 93 20:22:24 GMT

In article <1993Dec31.202224.813@cs.wisc.edu> jcargill@oka.cs.wisc.edu (Jon Cargille) writes:

   Does anyone have any experience with double-speed CD-ROM drives?  If
   so, what sort of bandwidth are you seeing from the drive?

   The reason I ask is that I recently purchased a Toshiba 3401b, which
   is supposed to achieve 330Kb/s.  However, when I use "dd" to read from
   the raw device, I get only about 200Kb/s.

   Is anyone else getting better performance from a similar drive?  If
   so, what sort of speeds do you see when you execute:

	   dd if=/dev/cd0d of=/dev/null
                      ^^^^<--????(Real Raw Device?)
                    
If you want see *sort of bandwith* for Toshiba 3401b, you have to
dd through the Real Raw Device like follows.

	bash# time dd if=/dev/rcd0a of=/dev/null bs=64k
	1105+0 records in
	1105+0 records out
	72417280 bytes transferred in 214 secs (338398 bytes/sec)
        214.79 real         0.02 user         1.21 sys
	bash# 

	Note: NetBSD0.9 + bt742a + 486 33Mbytes + 256KB Cahche 32Mbytes DRAM
              on kterm(Kanji xterm) + Xfree86 2.0

   Thanks for any info,

I hope you have *A Happy New Year* ;-)

   Jon
   -- 
   -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.
   Jon Cargille		jcargill@cs.wisc.edu
   Want your .sig compressed?  Reasonable rates
   and fast turnaround. Call today!

Atsushi.
-- 
Atsushi Murai                                          Email: amurai@spec.co.jp
System Planning and Engineering Co,.Ltd.               Voice: +81-33833-5341