Re: what's a mainframe, was is Vax addressing sane today

According to Stephen Fuld  <sfuld@alumni.cmu.edu.invalid>:

IBM definitely cared about maximum performance in the 1950s and early

1960s.
>
Yes.  And remember, one of the goals of S/360 was to provide an
architecture that could handle both scientific (i.e. compute bound) and
business (i.e. I/O bound) workloads.

I don't think anyone would have forseen how quickly scientific computing
moved to mini and micro computers with fast CPUs and weak peripherals.
Perhaps once the RAM is big enough to hold all the data the I/O performance
is not a big deal.

they knew they had a problem. The /95 and /195 were minor upgrades of

the /91 but that was the end of their supercomputer efforts.
>
Mostly true, except for the 3090 vector facility.

I suppose.  A review from the USDOE said:

 The IBM 3090 with Vector Facility is an extremely interesting machine
 because it combines very good scaler performance with enhanced vector
 and multitasking performance. For many IBM installations with a large
 scientific workload, the 3090/vector/MTF combination may be an ideal
 means of increasing throughput at minimum cost. However, neither the
 vector nor multitasking capabilities are sufficiently developed to
 make the 3090 competitive with our current worker machines for our
 large-scale scientific codes.

https://www.osti.gov/biblio/5039931

instruction, and the program doesn't notice.  I think you'll find a

pattern since the

CDC shock of making CPUs fast enough to keep the RAM and I/O devices

busy while having

the error checking and recovery features so the systems keep running

for years at a time.
>
Yes, but they also have to keep producing faster and faster CPUs so they
can entice current customers to upgrade and thus meet their revenue goals.

The memories and disks keep getting bigger so it's not totally silly to
think that the CPUs need to get faster, too.  They keep increasing the
number of CPUs, with z16 topping out at 200, all sharing up to 40TB of RAM.

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