Subject: Re: VAX 6460 being slow, IO bottlenecks and SMP woes ...
To: Thor Lancelot Simon <>
From: Johnny Billquist <>
List: port-vax
Date: 03/21/2002 10:46:09
On Thu, 21 Mar 2002, Thor Lancelot Simon wrote:

> On Thu, Mar 21, 2002 at 03:37:30AM -0500, John Klos wrote:
> > > > It wasn't. It does thing that today's desktops can't do. When is the
> > > > last time you got 99.999% uptime out of a PC?
> > >
> > > Not counting an eight-hour power failure, one of my PC-based servers
> > > has had under two minutes of unscheduled downtime in seven years of
> > > 24x7 operation.  That's better than 99.9999%.
> > 
> > But the point is that you cannot count on it. If PC hardware works for
> > seven years without fail, that is definitely the exception and not the
> > rule. PC hardware is generally mediocre. Even my Amiga hardware screams
> > quality next to PC hardware.
> Oh, and I suppose DEC hardware is all of exemplary quality?

I would not be as presumptions as to not pretend that DEC some pretty bad
engineering sometimes.

The RA81 was as bad, or perhaps even worse than the RA80.

But... The PDP-11s are very reliable, and many are still in use. Sure,
older and simpler technology...

On a VAX note, the 8600 series have some very serious stuff built in. Most
data paths and hardware logic have backups. If something in the machine
breaks (such as an ALU, or some important data path, or some register
storage) the machine uses alternate hardware and logs a hardware problem
that should be addressed at the next PM.
Diagnostics for the machine usually can pinpoint the exact chip that is

That machine is really an example of good engineering! No PC will come
close to it, even today.

And it does give you information on both incoming temp, and outgoing temp
at multiple places, along with power ratings for each power supply. (Yes,
PCs can do that more or less today, but I've yet to see one give *as much*
information as the VAX.) And depending on that information, the machine
can be informed that the power will be cut shortly (1 min, 5 min or
whatever) so that the system can be brought down orderly.

And if we speak small VAXen, the MVII seems to just tick on. Disks are
usually the big problem with them. Can't really blame DEC much for that.


Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email:           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol