On Sun, 2002-12-15 at 00:43, Mr. Adam ALLEN wrote: > On Sat, 2002-12-14 at 21:54, John H. Ingersoll, Jr. wrote: > > Running RH 8.0 on a Compaq Presario 7470. > > > > KDE -> Preferences -> Information -> Processor ID's my > > AMD K6-2 as "CPU family 5". Is this saying it's a > > pentium - not a pentium-II class processor? > > > > I remember back in the day when AMD-K6-3 was a new processor it was > marketed as better performing than an equivalent Intel PII - however it > is classified as an i586- so i686 RPM's are not a good idea. > The K6 family does NOT support some instructions of the Pentium Pro and later processors (except for the Pentium MMX) so if you use 686 binaries on a K6 they will crash. > As far as I remember there is a "k6" optimisation when compiling, though > how much difference there is between i586 and k6 and i686 is one for > debate by those who care and understand more than I do. > > > My concern is with installing RPMs optimized for i686, > > whether this will cause any problems. > > > > Up until now, I've always stuck with those optimized > > for i386 (i.e. generic) or i586. > > > The 386 RPMs are not optimized for the 386. They are optimized for the PII/PIII/Celeron family ie when deciding how to generate code Gcc bases on the 686 timetable. It just doesn't use the whole instruction set. 686 RPMs are compiled with the whole instruction set but on most programs this brings only minimal improvements respective to programs optimized for the 686 buyt with 386 instructions. Thus only when there are processor-specific parts written in assembler (whose use impedes running on a lesser procesor) does it make sense to compile for i686. My experience is that the K6 family gets very good performance from binaries optimized for the 686 (with 386 instructions) like those you get with Redhat, nearly as good as when optimiezd specifically for the K6 , quite better than when optimized for the 386 and _far_ better than when optiized for the Pentium (even with whole instruction set), so you could test replacing your 586 RPMS by the 386 versions. YMMV because there are assmebler parts in those RPMs JFM > > > > -- > NAME : Adam Allen. > EMAIL : adam@dynamicinteraction.co.uk > > COMMENT : ~~~~ insert your favourite signature comment here ~~~~ > > PGP : http://search.keyserver.net:11371/pks/lookup?op=vindex&search=adam%40dynamicinteraction.co.uk > -- Psyche-list mailing list Psyche-list@redhat.com https://listman.redhat.com/mailman/listinfo/psyche-list
