Dear all: Bill Rea just sent me a binary of Mlucas 2.7a which will run under Solaris 2.5 - apparently a lot of the older Sparcs still run this version of Solaris, and the binary compiled for Solaris 2.6 and 2.7 won't run under 2.5. This binary (like all the others) is available via ftp://209.133.33.182/pub/mayer/README.html Bill also sent me a detailed set of per-iteration timings for the above binary on a 167MHz Sparc 1 with 512KB L2 cache. These timings are quite interesting. For FFT lengths below 256K, the Sparc 1 behaves very similarly to an Alpha ev4. But above 256K the ev4 performance suffers somewhat of a deterioration, whereas the Sparc 1 keeps chugging onward: at 320K the Sparc timings match those of my 200MHz Alpha ev4, and above 320K they are significantly better, despite the Sparc's slightly lower clock speed. Perhaps this is the Sparc 1's non-blocking cache at work. The Sparc 1 also has a near-linear iteration time trend up to very long runlengths, and beyond 1024K has virtually identical relative performance (normalized by clock rate) as a state-of-the-art Sparc E450 with a much bigger 4MB L2 cache. Interesting... The upshot is that older Sparcs can still contribute quite valuable work for GIMPS: on a 167MHz Sparc 1 as above, double-checking an exponent ~5M should take about 3 weeks. First-time testing an LL exponent ~10M should take around 3 months, which is long, but still quite a bit faster than my P166 laptop needs, and well within the 120-day limit for manual test assignments. (And such assignments can also be extended by up to another 120 days, if need be.) Complete timings are at ftp://209.133.33.182/pub/mayer/gimps_timings.html Cheers, -Ernst p.s.: I would also appreciate some timings for SGI workstations with pre-R10000 MIPS processors. If you have an SGI with a MIPS 3000 to 8000 version CPU and want to do some timings, please do all the 128K-4608K FFT length timing tests listed on the README page, and send them to me, along with the output of the Irix 'hinv' command. _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
