[Info-vax] Why it is a good idea that OpenVMS isn't on x86-64 just yet

[William Pechter]

In article <27a17012-6e3e-4283-885e-62df13ecb2b2 at googlegroups.com>,
abrsvc  <dansabrservices at yahoo.com> wrote:
>On Monday, January 18, 2016 at 12:00:11 PM UTC-5, Johnny
>Billquist wrote:
>> On 2016-01-18 15:00, Kerry Main wrote:
>> > Most system vendors systems are driven by marketing and positioning
>> > to target markets.
>> >
>> > One possible example is things like removing NOOP's in
>ucode, adding a
>> > few tweaks & selling the new ucode as an enhancement to an existing
>> > system. Yes, they might throw in a new label to attach to
>the system, add
>> > new p/n's etc so it has the appearances and justification
>for the $'s spent.
>> >
>> > They might also do things like purposely slowing down benchmarks on
>> > one system so that a more favored system from the marketing groups
>> > is easier to position as "better".
>> >
>> > Pure speculation of course ..
>> >
>> > :-)
>> 
>> Oh, I know the stories. There have been plenty over the years.
>How many 
>> of them actually are true is a different story, though...
>> 
>> For the 11/750, I seriously doubt this would have been the
>case, but I 
>> obviously don't know for sure.
>> But let's say the VAX-11/750 could perform on par with the 11/780. 
>> Wouldn't have made much more sense to just price the 11/750 a little 
>> cheaper than the 11/780, and just stop producing the 11/780.
>The margins 
>> on the 11/750 would have been much greater, since it would
>cost way less 
>> than the 11/780 to produce.
>> So customers would have gotten the same performance at a lower price, 
>> and DEC would have made much more money... Can't see how they
>could have 
>> refused that.
>> 
>> 	Johnny
>
>IIRC the 750 was about 80-90% of the capacity of the 780 in
>terms of CPU speed.  The benefit was both the smaller footprint
>as well as not requiring anywhere near the same AC.  The 750 was
>also limited in its peripherals.  The 780 had both MassBus and
>UniBus. The 750 was restricted to the Unibus.

If I remember we had 11/750's with RH750's giving them Massbus
until the CI750 and UDA-50 moved in and "obsoleted" that for most 
folks.

>
>The bottom line was "similar" performance at less cost both of
>the actual machine as well as ownership (AC, power etc.) which
>mafde it much more affordable for the masses.
>
>Dan

I think the 11/750 limiting factor was memory size until the 64k drams.

The uVaxII pretty much made it possible to put 3 or so uVaxes in the 
same space as a small 11/750 -- so it pretty much killed the 11/750.

The 11/780 was slow but many were retrofitted to 11/785's for about
a 50% speed upgrade.

The 11/750 would've been interesting if it had a uVax board (or two or
three that could replace the CPU -- making a TRI-SMP Vax in the
cabinet of the 11/750.

Never heard of any proposed 11/750 cpu kickers -- the gate arrays
seemed to be a performance and diagnostic dead end.  The rest of
the board often failed first and replacing gate arrays was rare on
my site... Did about 1 in 6 years in Field Service IIRC.


Bill

-- 
-- 
Digital had it then.  Don't you wish you could buy it now!
pechter-at-gmail.com  http://xkcd.com/705/