On Tuesday 18 December 2012, [email protected] wrote: > I would like to know if some of you use a real time linux > distribution with Gnucap ? > > I was thinking about RTLinux, on the other hand i was > thinking about using a Gentoo, do you guys have any idea > about performance gain and what compilation options to use > to make Gnucap as fast as possible !
I haven't tried it but I think Orestes is correct. If you really want "as fast as possible" you could help it by carefully choosing the options and simulation parameters. A few pointers ...... 1. Minimize the output .... Select only the probes you want. 2. For a transient analysis, (bad hangover from spice syntax) specify a VERY LARGE step size, but add the option "trace all" which prints every data point. This may seem backwards, but gnucap's step control does a good job at determining the best stepping. If you manually specify a step size smaller than needed, it will run slower. 3. The stable version 0.35 reads in faster than the snapshot. Known problem, known solution, will be fixed. 4. Make sure you set the compile options for speed, in particular, asserts off "-DNDEBUG". The default is to do it this way, but check to be sure. The debug build (asserts and trace on) is about 2x slower. For the future, maybe .... I have considered using "MPTL" to support multiprocessors. There are several spots where it should be a simple matter of substituting a MPTL loop for a for or STL loop. The code is designed with parallel in mind, but I have not had the time to follow through. Two key places .. one is parallel model evaluation, the other is to split the matrix into sections and solve the sections in parallel. The split already happens. Need to do the rest. Still, that's at best only a linear function of how many processors. At worst, it might even be slower. http://spc.unige.ch/doku.php?id=mptl _______________________________________________ Help-gnucap mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-gnucap
