[net.micro.att] compiler speed on the 7300

richmon@astrovax.UUCP (Michael Richmond) (05/18/85)

   I went to play with the 7300 at my local computer store yesterday and have
some (dis?)heartening news for people like me who want to do a lot of
program development on the machine. The compile times for a simple program
consisting of nothing but lines like

               printf("hello there\n");

is (for 7300 in window environment, 7300 out of window environment and VAX
11/750 (out of window environment :-) ))

                     7300 w/ windows             7300              VAX

65 statements                                     :28              :09
250 statements           1:58                     :55              :21

   The number that really gets me down is the figure for 7300 performance
with windows (the 'user agent') running. It seemed that there was a lot of
disk activity in the window environment even when I was doing nothing - 
I'm not sure what the CPU was doing, but it ate up cycles like crazy.
Perhaps nice-ing up large compiles would help, but by how much? Has anyone
else done tests to compare with this rather simple-minded one?
   I was expecting somewhat faster times from the 7300, especially in the
window environment where I'll be doing most of my work (oh, yes, I decided
to get one anyway), but perhaps I was being unrealistic. I'd be willing to
bet that a comparison of execution times for would put the 7300 in a better
light, but for development that isn't nearly as important. Ah well.
-- 
Michael Richmond			Princeton University, Astrophysics

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richmon@astrovax.UUCP (Michael Richmond) (05/20/85)

  In response to several questions I've received, I ought to have mentioned
that the times I posted were for a 7300 with (so I was told) 1 Meg and the
20 Meg hard disk. I shudder to think of the performance with 512 K.

-- 
Michael Richmond			Princeton University, Astrophysics

{allegra,akgua,burl,cbosgd,decvax,ihnp4,noao,princeton,vax135}!astrovax!richmon

mash@mips.UUCP (John Mashey) (05/20/85)

Michael Richmond writes:
>    I went to play with the 7300 at my local computer store yesterday and have
> some (dis?)heartening news for people like me who want to do a lot of
> program development on the machine. The compile times for a simple program
	....
> is (for 7300 in window environment, 7300 out of window environment and VAX
> 11/750 (out of window environment :-) ))
>                      7300 w/ windows             7300              VAX
> 65 statements                                     :28              :09
> 250 statements           1:58                     :55              :21

It's hard to tell what this means, because the 7300 times are significantly
higher than for its ancestor-Miniframe, even at the same clock speed and
using the same compiler.  What I'd suspect is a high paging rate on a small
system.  I'd suggest redoing the experiment, doing the following:
1) Specify the size of the 7300.  For whatever reasons, doing C compiles
has a fierce knee inthe performance curve.  512K is tight, 1MB is OK.
2) What's OS on VAX? Be warned that the System V linker can often take
50-65% of the time on a minimal compile, whereas BSD linkers are not as
powerful, but are faster.  To measure this, try timing cc -c.
3) It's also worth reporting cpu as well as real.
-- 
-john mashey
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