Re: A very slow program
Paul <[email protected]> Wed, 2 Oct 2024 06:37:46 -0400
| Newsgroups | alt.comp.lang.c,comp.lang.c |
|---|---|
| Organization | A noiseless patient Spider |
| Message-ID | <[email protected]> |
On Wed, 10/2/2024 6:16 AM, Vir Campestris wrote: > On 16/09/2024 06:22, Paul wrote: >> Good prime code, comes with its own timing routines 🙂 >> >> http://cr.yp.to/primegen.html >> >>    http://cr.yp.to/primegen/primegen-0.97.tar.gz >> >>   Paul > > I pricked my ears up when I saw this - I've been spending a quite ridiculous amount of time tuning prime code. > > Happily for my sanity the program I published over on comp.lang.c++(1) is quite a bit faster than that one. On the other hand, I'm tuning for modern processors, and the comment in there say inter alia "It generates the 50847534 primes up to 1000000000 in just 8 seconds on a Pentium II-350" > > I don't remember the last time I saw one of those. > > <https://en.wikipedia.org/wiki/List_of_Intel_Pentium_II_processors> > > tells me it was release in 1998... > > Andy I started on PCs, with a Celery 300 for home use. That was the one that didn't have cache. And the generation before I got a machine, there were cache DIMMs for adding a cache function, and the cache DIMM in some cases, only covered half the address space, instead of covering the whole thing. The things you have to put up with. Paul