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From: src@scuzzy.in-berlin.de (Heiko Blume)
Newsgroups: comp.periphs.scsi
Subject: Re: SLOW WRITE ON OPTICAL ERASABLES
Keywords: OPTICAL, PERFORMANCE
Message-ID: <1991Jun15.173019.27914@scuzzy.in-berlin.de>
Date: 15 Jun 91 17:30:19 GMT
References: <1080@camco.Celestial.COM>
Organization: Contributed Software
Lines: 24

bill@camco.Celestial.COM (Bill Campbell) writes:
>I'm in the process of evaluating erasable optical drives.  The
>first drive I've installed is a Ricoh RO-5030E2, and I'm
>surprised at how slow it is writing. 

[benchmark]

>Is this typical of erasable write speeds?  I expected them to be
>slow, but not this slow!  Even removing a file from a directory
>seems to take a long time while it updates the directory entry.

magneto-optical recording has a problem: before writing data to
a spot that spot must first be erased. that means if you want
to write a block, it takes at least one full revolution + 1 block
of the disk. on average 1.5 revolutions are needed, which causes
the slow writing you experienced.

the 'solution' is to use a different method like phase-change
recording. for details see BYTE November 1990, page 289.
-- 
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