Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watmath!clyde!rutgers!princeton!udel!gatech!hubcap!lls
From: lls@hubcap.UUCP
Newsgroups: comp.hypercube
Subject: How to time on the NCUBE?
Message-ID: <693@hubcap.UUCP>
Date: Thu, 19-Nov-87 13:38:39 EST
Article-I.D.: hubcap.693
Posted: Thu Nov 19 13:38:39 1987
Date-Received: Sat, 21-Nov-87 16:03:21 EST
Sender: fpst@hubcap.UUCP
Lines: 26
Keywords: NCUBE, Performance
Approved: hypercube@hubcap.clemson.edu

All of you NCUBE users out there - This one is for you!

I am finally getting some programs to run on our NCUBE (in C).  I want
to do some timing - and have some questions:

1) How does one time on the host?  I am currently using the time() function,
but that only gives me accuracy to the nearest second - I need to get to
clock ticks or at least to msecs.  My programs are only take 1 or 2 seconds,
and I cannot tell the difference between using 1 or 8 processors when
measuring overall time....

2) I am using the ntime() function on each node.  This at least gives me
clock ticks and lets me measure the amount of time spent on each node -
However, I have noticed that my times linearly increase from node 0 to
node 7 (I have an 8 node system) - Why would this be?  All nodes have
the same amount of work (totally balanced problem).  Is it because of
the communication - node 0 gets its data first and processes it before
the others get their data - hence the linearity?

Any suggestions on how to measure the performance on the NCUBE would
be appreciated.  I don't want to add in so many timing monitors, that
it affects the performance.

Thanks,    

- Lauren Smith