On Wed, 26 Jun 2002, at 12:42pm, Derek D. Martin wrote:
>  IOW, with the speed of CPUs today, does a hardware-specific chip really
> have any practical functional benefit (ignoring cost, which is not a
> functional benefit) over a more generalized one, for any of these
> applications?

  Yes.  Resource contention.  A card that offloads tasks to the CPU has to
contend for said CPU along with memory, bus, and other resources.  If a time
critical event happens when the system is busy, the event is lost.

  This is why, even in a host system with an extremely fast clock rate and
gobs of memory, so-called "Winmodems" still suck.  A modem does not require
a huge amount of processor power to do what it does, but it *must* be able
to do it when the signal comes in from the analog-to-digital converter.  If
the system is busy doing something else, you lose.

  In fact, in high-end systems, you will see even more tasks offloaded to
secondary processors, because it is easier and cheaper to do that then it is
to make the core system faster.  Hence things like hardware RAID
controllers, "smart" serial controllers, and network cards with built-in
encryption ASICs.

> But I think that doesn't diminish Ben's point, which I interpreted to be
> that specialized hardware isn't necessarily inherently better than the
> same task implemented in software on generalized hardware.

  My point was not so much that, but rather, that everything has an
implementation cost, whether implemented in hardware or software.  
Implementing something in hardware does not magically make that cost go
away.

  And, I guess I should add, implementing something in software is not
automatically a good idea, either.  :-)

-- 
Ben Scott <[EMAIL PROTECTED]>
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