Dear GIMPSers: I am pleased to announce Mlucas 2.7b (source code and binaries for selected platforms) is available. See ftp://hogranch.com/pub/mayer/README.html ftp://hogranch.com/pub/mayer/gimps_timings.html (768kbps capacity) or the mirror at ftp://209.133.33.182/pub/mayer/README.html ftp://209.133.33.182/pub/mayer/gimps_timings.html (160kbps capacity). The major differences from v2.7a are: 1) New FFT radices, including ones of the form (11,13,15)*2^n. Thus every interval between adjacent power-of-2 runlengths can be split into roughly eight equal pieces. Folks testing exponents > 12.59M and double-checking exponents > 6.39M will (on all but a few of the older platforms) benefit from the new radix-11 capability. There are also new larger power-of-2 radices (32 and 64), which allow even very large runlengths (up to 2^23) to be handled with as few as 6 passes through the data. 2) Runtime performance optimization for the user's platform. The program now allows the user to choose from a reasonable set of possible radices which can be used at each runlength by changing a single entry in a configuration file. This can be done without interrupting the program - the file is reread each time a 2000-iteration checkpoint is reached, and if the prescribed radix set is different from the one currently being used, the code switches over and prints the actual new radices being used to the .stat file for the exponent in question. The elapsed time written to the .stat file at the next checkpoint can then be used to find the optimal radix set for the current runlength. Preoptimized configuration files for most major hardware setups on which the program has been tested accompany the precompiled binaries, so folks who don't want to fiddle around with this feature don't have to. Folks who do the runtime tuning will often be rewarded with a healthy speedup. If you peruse the timings page, you'll also see that Mlucas now has competition for the hearts and minds (well, mainly the CPU cycles :) of the RISC crowd. Guillermo Ballester Valor's excellent C program, Glucas, is showing excellent performance on most platforms, and even beats Mlucas on some. Mac/PowerPC users will be especially interested in Glucas, since it outperforms MacLucasUNIX except for a few narrow ranges of exponents, and (IMO more importantly) is being actively maintained and improved. Right now Glucas has only been compiled using the CodeWarrior C compiler (which I believe has the Gnu C compiler at its core - correct me if I'm wrong), and we're looking for folks to compile and do timings on various generations of the PPC chip, and also who have other compilers, such as the Absoft suite (whose Fortran-90 compiler could also be used to compile Mlucas for Mac.) Anyway, the above links have all the details. Right now I'm really bushed, so please excuse me while I go sleep for about 12 hours. Happy hunting, -Ernst _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
