Grab your Phillips, it's...
The Latest from The Screwdriver List!
Let's see...are apples better than walnuts?
* * *
The speed of rotation of a hard drive is just one of the things that
determines how "fast" the overall drive is.
In particular, half the rotation time is a minimum average latency (time
between requesting some information and actually getting it)--and that only
applies when the head is already on the right cylinder. Stepping from
cylinder-to-cylinder adds additional delays.
And the speed of rotation determines (along with the lineal density of data
along each track) sets the maximum rate at which data can be read from or
written to the disk. (This is the maximum sustainable speed. The burst
speed is set more by the buffer read/write speed, which is often very much
greater.)
Now to turn from fruits to nuts....
* * *
The bus connection (EIDE--which might be the original 33MHz version or it
could now be Ultra 66 or Ultra 100, versus SCSI--which also comes in
several flavors, UltraFast and UltraWide being the current "best" form
commonly available, I believe) limits how fast information can flow onto or
off of the drive subsystem.
SCSI has an advantage if you are simultaneously flowing information to
and/or from several attached SCSI devices. But if you are only using a
single drive, the best SCSI and the best EIDE are comparably fast, so far
as I can recall just now.
* * *
The details about these things keep changing, of course, but the principles
remain the same.
So there isn't a good, simple answer to your question--as is all-to-often
the situation!
Oh, and about slow transfers from digital cameras...the best solution if
you have to transfer images from SmartMedia, Compact Flash, PC Card or
almost any other such medium is to get a USB-connectable reader/writer for
that medium. Lexar makes a very good one that handles all three of the
media I just mentioned in a single box, and it transfers data faster than a
floppy disk and *much* faster than a serial connection. (I forget right now
exactly how fast, but it does move right along. And, when USB 2.0 comes
out, *if* Lexar upgrades the unit--or replaces it with a newer, faster
model--one may be able to do even better yet.)
John
At 04:24 PM 3/21/01 -0600, you wrote:
>Grab your Phillips, it's...
>The Latest from The Screwdriver List!
>
>
>I've got an Agfa, John. I really love the Clik, my last camera had Compact
>Flash and a serial connector. Talk about grow a beard while you waited for
>things to download!!
>On the same line of question: which type of hard drive is really the fastest?
>I have heard that the IBM 7200 RPM drives are the fastest. Are they faster
>than Scsi drives?
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John M. Goodman, Ph.D., author of "Peter Norton's Inside the PC," Seventh
Edition (Sams 1997, ISBN 0-672-31041-4), and Eighth Edition (Sams 1999,
ISBN 0-672-31532-7).
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That's all for now from The Screwdriver List
"Red Stripe to Pin 1"
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