gauging interest in VAX 6000-530

From: Peter Pachla <peter.pachla_at_vectrex.freeserve.co.uk>
Date: Mon Oct 25 11:12:28 1999

This thread is starting to get tedious, it was interesting to start with but
now seems to have degenerated into pointless argument.

Mike, you seem either to be rather ill informed or out to start a flame war.
Despite the fact that I have my arm in a sling and it's agony to type (result
of moving a piece of classic iron recently) I can't sit by and watch this pass
without making at least some comment. After which I'm filtering out this
thread....

So, to business.


>....I think single-user; I run single-user machines....

Exactly, Mike you're looking at just ONE sector of the computer world. What is
important to you is of no consequence to a vast number of other
people/corporations who need to support multiple users and process vast
amounts of data.

>....The future is single-user with vast network-accessed databases.

RUBBISH, you're making assumptions based on your own view of the industry. In
the real world there is a need for both single user systems/workstations AND
(comparatively) large multi user installations.

Both types of systems are targeted at different types of applications and both
will always have their place in the market.

But then, of course, I think you probably realise this and are just offering
us more flame bait?


> BUT, I would like the Vax Lover Crowd to acknowledge that they integer
> performance of their machine is pathetic.

More flame bait. Do you REALLY think that making assertions such as this is
going to make anyone on the other side of the fence anything but
defensive?????

As others have already pointed out, integer performance/MIPS/drystones etc is
NOT a good indicator of overall SYSTEM performance. THAT is what is of
importance at the end of the day.

A personal example....in the mid '80s I was working in the video games
industry writing software for Atari and Commodore systems (Atari 8-bit,
C64/+4, Atari 7800). I used to assemble my programs on the Atari and transfer
them to the target system rather than use a cross assembler on a PC. Why?
Because although the PC I had access to ran a V20 at 8MHz compared to the
rather pedestrian 1.79MHz of my Atari's 6502 the PC took roughly 4 times
longer to do the same job - even with the obvious advantage of having a hard
drive. If you want the damn figures I expect I still have them somewhere
(though it would mean digging out my Atari system to access the data).

It was a simple case of superior SYSTEM architecture.


>> Its not the speed of the individual bus, but its the number
>>of busses.
>
> That's of course bull.....
>
>>The more busses, the more parallelism and the less waiting.
>
> -IF- the speed of the busses is high enough!

It depends entirely on the system architecture.

Two 1MHz busses will be faster than a single 2MHz bus if they are being used
for different purposes, such as one for I/O and one for memory accesses.

Particularly in the case of the PC the single expansion bus is a major
bottleneck. The original design had all I/O, memory, memory refresh etc ALL
done over a single bus.

Although things have gotten a lot better with the introduction of MCA, EISA,
VL and PCI, separate RAM busses etc there's still a long way to go. We still
effectively have a single bus down which we're trying to shovel the majority
of our data.


>After all, at -some- point, all these busses have to get their data
>into/out of the CPU....

No, at some point all these busses have to get their data in/out of MEMORY.
Polled/interrupt driven I/O is at best extremely wasteful of processor
time....this is why I personally use SCSI in my PC in preference to IDE (which
makes it ALMOST usable).


>....and it does show that there are other busses available on a
>PC, yes? (Which was my original point.)

But with just ONE bus in the system you STILL have a bottleneck.

It doesn't matter how many lanes you have on a single motorway, or how fast
your car is, when you have a lot of traffic on the road you still get traffic
jams and major bottlenecks at junctions and on/off ramps....


  TTFN - Pete.

--
Hardware & Software Engineer. Sound Engineer.
Collector of Arcade Machines, Games Consoles & Obsolete Computers (esp DEC)
peter.pachla_at_wintermute.org.uk            |
peter.pachla_at_vectrex.freeserve.co.uk      |
peter.pachla_at_virgin.net                   |
peter.pachla_at_wintermute.free-online.co.uk | www.wintermute.free-online.co.uk
--
Received on Mon Oct 25 1999 - 11:12:28 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:32:34 BST