Quoting Ian C. Sison ([EMAIL PROTECTED]):
>>> ...faster access (UDMA 133)....
>>
>> A mirage and an irrelevancy. That's the theoretical maximum transfer
>> rate of the bus, which can never be approached even in ideal cases,
>> because data flow is limited to the physical read speed of hard drives,
>
> An issue which is just as relevant on SCSI based solutions
No, that's _exactly_ where there's a big difference, because of
disconnected operation. When you say "UDMA 133" is "faster access",
that is completely meaningless, because only one device on the bus can
be active at a time. Demand on bus bandwidth can never be additive,
even in ideal configurations.
Because of SCSI disconnect, one might be potentially drawing data at the
maximum physical read speed from several drives on the chain. Thus, any
limit on bus bandwidth has some chance of being meaningful, since the
bandwidth consumption of multiple drives on the chain can be additive.
>> I hear of some contrived test situations where it's starting
>> to be possible to saturate ATA/66, but just barely.
>
> Most Hardware IDE RAID controllers recommend one disk per ATA channel
> anyway, so it's a non-issue.
That is _utterly_ irrelevant to my point, which is that claims that the
latest ATA extension is "faster" (because of theoretical bandwidth
maximums that can't be even remotely approached by the single active
device possible on each chain at any time) are meaningless. Thus: a
mirage and an irrelevancy.
There might be excellent reasons to deploy ATA in a given situation.
However, you happen to have cited one of the erroneous and meaningless
ones.
--
Cheers, "Learning Java has been a slow and tortuous process for me. Every
Rick Moen few minutes, I start screaming 'No, you fools!' and have to go
[EMAIL PROTECTED] read something from _Structure and Interpretation of
Computer Programs_ to de-stress." -- The Cube, www.forum3000.org
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