"Carroll, Barry" <[EMAIL PROTECTED]> wrote

> IBM's mainframes are now constructed out of massively pararallel 
> arrays
> of MPUs.  In other words, all that number crunching is done by 
> hundreds
> or thousands of souped up PCs, all connected together and stuffed 
> into a
> single box.

The processors may be the same, the architecture is significantly 
different.
Data, memory and programs all have their own busses etc for one thing
and there are multiple IO channels for disk along with multiple DMA
controllers and in some cases dedicated ALUs and FPUs alongside
those built into the chips. All of which keep the data sliding along
smoothly.

These are all part of the reason that mainframes often look slow
on paper - often with 1GHz CPUs etc - but the architecture around
them more than compensates for the data processing they are
designed for.

I find it interesting that in our company we have been able to 
gradually
replace (over a 15 year period) a suite of 30 mainframes with 3. And
we only really use 3 for resilience/backup reasons!

Alan G.



_______________________________________________
Tutor maillist  -  Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor

Reply via email to