I think the original answer was more to the point of Performance Limitation.
The mechanical delays inherent in the disk rotation are much slower than
the electronic or optical speeds in the connection between disk and
computer.
If you had a huge bank of semiconductor memory, or a huge cache or buffer
which was really helping (i.e., you wanted the information that was already
in the cache or buffer), then things get more complicated.
BobG
On Thy, May 04, 2000 at 12:26:11 -0700 Philip Edelbrock wrote:
>On Thu, May 04, 2000 at 08:35:52AM -0700, Carruth, Rusty wrote:
>>
>> > The primary limitation is probably the rotational speed of the disks and
>> > how fast you can rip data off the drives. For instance, ...
>>
>> Well, yeah, and so whatever happened to optical scsi? I heard that you
>> could get 1 gbit/sec (or maybe gByte?) xfer, and you could go 1000 meters -
>> or is this not coming down the pike?
>>
>> (optical scsi - meaning using fiber instead of ribbon cable to interconnect
>> controller to drive)
>
>Optical is an interesting idea. Fiber has a better throughput (I
>think the limiting factor is the LED/laser modulation), but fiber has
>a longer latency. I.e., light travels slower in fiber than
>electricity through wire. (No, light doesn't travel at 'light speed'
>through a dense medium like plastic or glass.) But you can pack more
>data in a fiber. (I.e., more on-off transitions per second.)
>
>I think fiber is mostly used for running long distances, or for
>isolating (electricly) between nodes/networks. Some NSP's require
>that your link be fiber to prevent the possibility of you frying their
>equipment if you, say, wire your DS1 (T1) pairs to an electrical
>outlet.. ;')
>
>For shorter distances, I think differential pairs of wires is
>faster/cheaper/easier for most things.
>
>
>Phil
>
>--
>Philip Edelbrock -- IS Manager -- Edge Design, Corvallis, OR
> [EMAIL PROTECTED] -- http://www.netroedge.com/~phil
> PGP F16: 01 D2 FD 01 B5 46 F4 F0 3A 8B 9D 7E 14 7F FB 7A
