"vi" & Supercomputer Performance

[Mike Muuss]

Carl -

The problem with your argument is that you implicitly assume
that it is cheaper to transfer an entire file to another machine,
than it is to do a little editing on the file on the Cray.

In my measurements (Cray XMP48 running COS 116, Cray XMP48 running
UNICOS 3, 4, and 5, Cray-2 running UNICOS 4 and 5), for "medium" sized
source files, it actually used *less* Cray time to suck the file into
a screen editor (JOVE and VI were tested), modify a "few" lines,
and write it back out, than it was to move the file to a "front end"
and then back to the Cray.  (obviously, no screen editor on COS,
I just measured file xfer times, and found it more expensive of
Cray CPU time than a UNICOS FTP or RCP).

Now, I would not suggest developing new code from scratch on the Cray,
nor would I suggest using the Cray for document processing, but
there is no reason in the world that Cray users should not be allowed
to modify their Cray files using the Cray!  Keep the bloody intermediate
machines (err, "front ends") out of my way, please.

Obviously, new code and document processing should be done on your
workstation.
	Best,
	 -Mike Muuss
	  U. S. Army Ballistic Research Lab