[HECnet] Another TOPS-10 DECnet problem

[Johnny Billquist]

And where I'm from we were regularly running 40 people on one 11/70 with 
RSTS/E, and on bad days we were above 60. But then it was miserably slow...

And yes, I have plenty of memories of the mails between MRC and BAH. :-)

   Johnny

On 2021-11-11 23:48, Thomas DeBellis wrote:
> Oh, that old cat fight?  Meow!!  I'm walking away from it; I don't know 
> how much email got spewed between MRC and BAH about it.  I don't think 
> either side ever got the point that you are not comparing apples to apples.
> 
> Having looked at both schedulers, I don't immediately see that either 
> was more efficient than the other.  There clearly was cross 
> fertilization in a number of areas.
> 
> Recall that Tops-20 has processes and that a job may have a large number 
> of processes.  The number of jobs then is not going to be a valid 
> comparison.  For example, let's take a look at Galaxy on Tops-10, which 
> occupies 10 job slots:
> 
> Job    Who     Line#    What   Size(P) State   Run Time
> 
>   1    [OPR]     DET     NEBULA  26+40   HB 0
>   3    [OPR]      0      QUEUE   9+38    ^C 1
>   7    [OPR]     DET     QUASAR  40+40   SL 1
>   9    [OPR]     DET     PULSAR  5+40    HB SW 0
> 10    [OPR]     DET     ORION   109+40  SL 0
> 11    [OPR]     DET     NML     15+18   HB 3
> 13    [OPR]     DET     CDRIVE  30+40   HB 0
> 14    [OPR]     DET     FAL-10  104+40  SL 1
> 
> 
> They're all underneath a _single_ job on Tops-20 or built into the EXEÇ, 
> but producing the same load because it is the same code.
> 
> We did do some instrumenting and we found that the snazzy parsing 
> (COMND%) was not contributing that much to load.  There was some 
> overhead simulating UUO's, which are obviously natively executing on 
> Tops-10.  Nearly all editing was done with WYSIWYG video editing, which 
> surely must produce more load than TECO or SOS.  Some work was put into 
> TEXTI% to mitigate the context switching.
> 
> MRC's position was that Tops-20 was doing more, but I'm not sure how 
> comfortable I am with that.  Having used and programmed both, I think 
> it's more like 'doing differently'.  I would say that it was rare to 
> find people who could easily move between the two and/or who weren't 
> highly opinionated.
> 
> It's a waste of time; you bought what did the job best for your 
> environment.  It's kind of like apples and pineapples; they sound the 
> same but they're just not.
> ------------------------------------------------------------------------
> On 11/11/21 5:20 PM, Robert Armstrong wrote:
>>
>> >You had a 20 that would handle 600 students in 1977/???/
>>
>>   I think he said something about six 20s…  I’m pretty sure there’s no 
>> way one CPU would have handled 600 timesharing users.   We could get 
>> to around 120 on a single KL10E with TOPS-10 before it got unbearably 
>> slow.  With TOPS-20 on the same hardware we could only get to 80 or 
>> so; TOPS20 was something of a pig.
>>
>> Bob
>>

-- 
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