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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.<br>
<br>
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.<br>
<br>
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:
<p><font size="4"><tt>Job Who Line# What Size(P)
State Run Time</tt><tt><br>
</tt><tt><br>
</tt><tt> 1 [OPR] DET NEBULA 26+40 HB
0</tt><tt><br>
</tt><tt> 3 [OPR] 0 QUEUE 9+38 ^C
1</tt><tt><br>
</tt><tt> 7 [OPR] DET QUASAR 40+40 SL
1</tt><tt><br>
</tt><tt> 9 [OPR] DET PULSAR 5+40 HB SW
0</tt><tt><br>
</tt><tt>10 [OPR] DET ORION 109+40 SL
0</tt><tt><br>
</tt><tt>11 [OPR] DET NML 15+18 HB
3</tt><tt><br>
</tt><tt>13 [OPR] DET CDRIVE 30+40 HB
0</tt><tt><br>
</tt><tt>14 [OPR] DET FAL-10 104+40 SL
1</tt></font></p>
<br>
They're all underneath a <u>single</u> job on Tops-20 or built into
the EXEÇ, but producing the same load because it is the same code.<br>
<br>
We did do some instrumenting and we found that the snazzy parsing (<tt>COMND%</tt>)
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 <font size="4"><tt>TECO</tt></font>
or <font size="4"><tt>SOS</tt></font>. Some work was put into <font
size="4"><tt>TEXTI%</tt></font> to mitigate the context switching.<br>
<br>
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.<br>
<br>
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.<br>
<hr width="100%" size="2">
<div class="moz-cite-prefix">On 11/11/21 5:20 PM, Robert Armstrong
wrote:<br>
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<p><span style="color:#1F497D">></span>You had a 20 that
would handle <tt><span style="font-size:10.0pt">600</span></tt>
students in 1977<i>???</i> <span style="color:#1F497D"><o:p></o:p></span></p>
<p><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"> 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.<o:p></o:p></span></p>
<p><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Bob<o:p></o:p></span></p>
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