On 18.10.18 11:37, Steve Litt wrote:
> OK. Next question. What is the cost difference between a computer
> terminal and a low power computer with the muscle to run apps whose
> data is on the central server?

The price of hardware was entirely different back then, making re-use
much more compelling cost-wise. But the grunt wasn't there in my
experience. To go with an HP64000 microprocessor development system,
back in the 80s, I bought a small server with a (for then) big disk, and
four green terminals IIRC. The whitepaper extolling its virtues claimed
it'd be just spiffy for 4 users, with graphs, tables, and pages of text
to "prove" it. But in practice the 68040 CPU only sufficed for editing.
Once the team hit it with concurrent compiles, it died in the derriere.
>From then on, I was a convert to distributed processing, and sprinkled
sparcstations about instead. (OK, LAN was over co-ax back then, and an
unaware user could bring that down just by knocking the 50 ohm
termination off the T-connector on the back of his machine, if it was
the last on the run. Much easier to find if you'd run the cable, than if
you had to hunt for it.)

> If one uses terminals, how many users can a high power computer handle?
> 50? 100? On the other hand, if every user contributes enough CPU to run
> the apps, it could be thousands.

With CPU, RAM, and HD costing only beans now, we can can now give each
user what was then a supercomputer, for what they paid for a terminal.
Apart from the increased performance, even with what we had back then,
the fault tolerance inherent in distributed computing didn't escape my
notice, given responsibility for meeting project deadlines.

Another team did go for a humungous refrigerator-sized quad-cpu HP
compute server with 50 hard drives in a second refrigerator-sized
enclosure, but I stayed distributed. (The quad-cpu mobo was nearly a
yard square.)

Erik