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

[Johnny Billquist]

On 2016-01-18 19:45, John Reagan wrote:
> On Monday, January 18, 2016 at 1:16:26 PM UTC-5, Johnny Billquist wrote:
>> On 2016-01-18 18:23, abrsvc wrote:
>>>
>>> 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.
>>
>> I think the official numbers are 0.6 VUPS, while the 11/780 by
>> definition is 1.
>> But the 11/750 can take both Massbus and CI. So that would not be a
>> differentiating factor. However, you limited to (I think) one massbus
>> and three unibuses on the 11/750. (Or maybe it was one of each?)
>>
>>> 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.
>>
>> Well, buying and running an 11/750 was way cheaper. But I do remember
>> the feeling that they were slow. However, I mostly would have compared
>> that with an 11/785... Which obviously widened the gap.
>>
>> 	Johnny
>
> And don't forget those lovely TU58s.  You could also get an optional floating unit for native F&D (I assume most folks got the option?)

Argh! Thanks for reminding me... The onlyconsolation was that you didn't 
use it most of the time... I can't imagine running STABACKUP from a TU58...

> And I thought it was 1 Massbus and 2 Unibus maximum.

No, that it was definitely not. 1&3 I'm pretty sure now. I could of 
course look up the documentation, but where is the fun in that. :-D

It was the 11/730 and family that only had one Unibus, so the 11/750 was 
three. However, I don't know for sure if maybe adding the CI forced you 
to give up some of the others? But I don't think the RH750 excluded any 
Unibuses.

	Johnny

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