Date: Tue, 16 Jul 1996 10:14:14 -0700 From: "Michael L. VanLoon -- HeadCandy.com" <michaelv@HeadCandy.com> To: "Jordan K. Hubbard" <jkh@time.cdrom.com> Cc: Jason Thorpe <thorpej@nas.nasa.gov>, dunn@harborcom.net, "'hackers@FreeBSD.org'" <hackers@freebsd.org> Subject: Re: mitsumi CD-ROM Message-ID: <199607161714.KAA23015@MindBender.HeadCandy.com> In-Reply-To: Your message of Tue, 16 Jul 96 10:01:57 -0700. <20634.837536517@time.cdrom.com>
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>> Why? 8x on a IDE CD-ROM is 8x a "standard" (cough) IDE CD-ROM, which in
>> my experience, is roughly equivalent to a 4x SCSI CD-ROM :-)
>Hmmm. An interesting point. :-)
Actually, it's *supposed* to mean 8x the original CD-ROM transfer
speed, which is dictated by the speed the drive spins. 1x is 150KB/s.
8x is 1.2MB/s. It really is irrespective of the interface.
HOWEVER, that is only a small part of the equation. The speed
multiplier of the drive has no real correlation to the seek speed of
the drive, and all CD-ROMs have slow seek times (some much slower than
others, of course). So, it won't matter if your drive is 2x or 8x if
it spends 80% of its time seeking.
The only place that much extra speed becomes really useful is if the
drive is able to stream the data in from sequential tracks, such as if
a multi-media file was layed on the CD-ROM in a known sequential
fashion. Otherwise, if you're spending 200ms average, per seek, and
you're accessing a lot of files all over the disk, you might as well
have a 2x SCSI drive, save a little money, and get something that
doesn't dominate your CPU.
That's how I understand it anyway.
Besides, most of those newer IDE CD-ROMs I've seen on the market are
so cheap as to basically be disposable. The build quality is just
really awful in a lot of them.
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Michael L. VanLoon michaelv@HeadCandy.com
--< Free your mind and your machine -- NetBSD free un*x >--
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If you're in the Seattle area, ask me how.
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