zazula@uazhe0.physics.arizona.edu (RALPH ZAZULA) (03/29/91)
So I'm working on this neural-net problem and figure that the matrix multiplicatons I'm doing would be ideally suited for the DSP. I was curious just how much of a speedup I would get so I did a naive timing study using a modified /NextDeveloper/Examples/DSP/ArrayProcessing/matrix/matrix.c What I did was to loop over the DSPAPmtm call and the 'manual' calculation of the matrix-multiply and used time(3) to get the times. With a loop of 1000 iterations, the DSP takes 21 sec and the 030 takes 1 sec. What??? I said... So, maybe the loop got optimized out??? Nope. If I omit the -O qualifier *and* add the loop index to the matrix elements, thus insuring that the entire loop gets executed, I get the same results. So why does it appear that the DSP is running 20 (twenty) times slower than the 030/math-chip combo? NOTE that I did not include the DSPAPWrite/ReadFloatArray calls in the timing loop. These are documented by NeXT as being inefficient. Ralph |----------------------------------------------------------------------| | Ralph Zazula "Computer Addict!" | | University of Arizona --- Department of Physics | | UAZHEP::ZAZULA (DecNet/HEPNet) | | zazula@uazhe0.physics.arizona.edu (Internet) | |----------------------------------------------------------------------| | "You can twist perceptions, reality won't budge." - Neil Peart | |----------------------------------------------------------------------|
nates@sporobolus.NREL.ColoState.EDU (Nate Sammons) (03/29/91)
hey, I'm thinking of getting a NeXTstation, but I need to know something: Right now I am using a Mac SE/30 and am doing LOTS of mechanical design work on it with a program called MacBRAVO! (I have MODELER and DETAILER) It was ported to the mac from a VAX (on the VAX it is called BRAVO 3) but is now a mac-ish program.... Does anyone out there know if Schlumberger is planning a NeXT version? if so, tell me... if not, who is planning a 3D CAD package for the NeXT, and when will it be available?? must support 3D designing, and have a very powerful set of tools geared (no pun intended) toward the mechanical side of designing.... PLEASE HELP!!!! -Nate ************************************************************************ * Nate Sammons voice: (303) 482-6812 data: (303) 493-4325 * * * * nsammons@lobo.rmhs.colorado.edu * * nates@sporobolus.nrel.colostate.edu * * * * "deus ex machina" * * * ************************************************************************