Difference between IDE and SCSI ??

Tim ignored_mailbox at yahoo.com.au
Mon Feb 4 12:19:46 UTC 2008

>> speed in the, then, current serial circuitry.  If you could get faster,
>> and accurate electronics, which you *now* can, serial can manage faster
>> rates, easier and more reliably.

Alan Cox:
> No.

I don't think you read what I wrote.

> The reason is quite different. When you have a parallel cable all the
> wires are never quite the same length, diameter or metal properties
> (ditto tracks on a board). That means that the signals arrive at the ends
> of each wire at different times. Your clock rate is thus limited by the
> cable quality and length as well as these propogation delays. That is
> what limits PATA to UDMA/133. Any faster and the bits just won't turn up
> on time.

I know that.  But *IN* *THE* *PAST* serial devices were generally the
slower device, because the top speed that those devices could manage, at
that time was slower than the speeds of parallel devices.  At that time,
the parallel technology was faster than the serial technology.  Yes,
parallel still had those limits, but was still operating faster than the
current serial technology.  I'd certainly never come across personal
computers where the serial ports could move data faster than a parallel

If that weren't the case, we would have had other technologies than
parallel drive ports., etc., a lot earlier on.

(This computer runs FC7, my others run FC4, FC5 & FC6, in case that's
 important to the thread.)

Don't send private replies to my address, the mailbox is ignored.
I read messages from the public lists.

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