nagy%warner.hepnet@LBL.ARPA.UUCP (06/06/87)
We have PCA but I have not personally used it. A couple of others in my group have used it a bit and been pretty happy with it (their only complaint was that PCA, particularly the Analyzer, was pretty complex, i.e. lots of commands,d required a bit of playing with to get the results desired). I first learned of PCA at a DECUS session given by Digital describing the use of PCA to improve the performance of the VAX FORTRAN compiler and of PCA itself. As I remember, particularly in the case of PCA, the improvement factors were enormous and quite surprising (mostly as a result of eliminating excessive page faulting by changing memory allocation schemes and data structures) = Frank J. Nagy = Fermilab Research Division EED/Controls = HEPNET: WARNER::NAGY (43198::NAGY) or FNAL::NAGY (43009::NAGY) = BitNet: NAGY@FNAL = USnail: Fermilab POB 500 MS/220 Batavia, IL 60510
klb@philabs.UUCP (06/08/87)
I have used it and I think it's great! The commands are somewhat complex but after using it a few times you learn which ones you normally need to issue. It will prove to you that programmer intuition about what needs optimizing and what doesn't is terrible. I found that I was wasting my time trying to speed up sections of code that didn't need it, while the sections that did need it were the last ones I would have looked at. It really is worthwhile - it often shows the way to tremendous performance improvements with little effort.
tedcrane@batcomputer.UUCP (06/08/87)
We have PCA. I've used it a bit. There are a lot of commands, and
it may take a while to learn to use them all, BUT you can do the
most obvious kinds of inspection (like finding which line of code is
eating most of your CPU time) quite easily.
Several of our users have made use of PCA. In each case, it has helped
them identify problem spots. In some cases they were able to improve
performance as a result. Isolated code fragments were sped up up to maybe
six times (love that up up).
If tuning your program is within your time budget, and you can affort PCA,
we'd recommend it!
- ted crane, alias (tc)
tedcrane@squid.tn.cornell.edu BITNET: tedcrane@CRNLTHRY
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